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Cancer Patent Abstract
Cyclopenta[g]quinazolines of the formula (I):--wherein: A is a group
OR or NR.sup.0R.sup.1 wherein R.sup.0 and R.sup.1 are each independently
hydrogen C.sub.1-4 alkyl, C.sub.3-4 alkenyl, C.sub.3-4 alkynyl,
C.sub.2-4 hydroxyalkyl, C.sub.2-4 halogenoalkyl or C.sub.1-4 cyanoalkyl,
or R.sup.0 and R.sup.1 together with the intermediate N form a five-
or six-membered heterocyclic ring, p is an integer in the range
1 to 4, R.sup.2 is hydrogen, C.sub.1-4 alkyl, C.sub.3-4 alkenyl,
C.sub.3-4 alkynyl, C.sub.2-4 hydroxyalkyl, C.sub.2-4 halogenoalkyl
or C.sub.1-4 cyanoalkyl; Ar.sup.1 is phenylene, thiophenediyl, thiazolediyl,
pyridinediyl or pyrimidinediyl which may optionally bear one or
two substituents selected from halogeno, hydroxy, amino, nitro,
cyano, trifluoromethyl, C.sub.1-4 alkyl and C.sub.1-4 alkoxy, and
R.sup.3 is a group of one of the following formulae: -A.sup.1-Ar.sup.2-A.sup.2-Y.sup.1-A.sup.5-CON(R)CH(Y.sup.4)Y.sup.5-A.sup.-
8-X--Ar.sup.4 and pharmaceutically acceptable salts or esters thereof
are of therapeutic value particularly in the treatment of cancer
##STR00001##
Cancer Patent Claims
The invention claimed is:
1. A cyclopenta[g]quinazoline wherein the compound is: N-{N-{4-[N-(2-methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quin-
azolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-D-glutamic
acid; N-{N-{4-[N-(2-hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[-
g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-D-glu-
tamic acid; or N-{N-{4-[N-(2-hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quin-
azolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-N-methyl-L--
glutamic acid; or a pharmaceutically acceptable salt or ester thereof.
2. A pharmaceutical composition comprising a cyclopenta[g]quinazoline
according to claim 1 together with a pharmaceutically acceptable
diluent or carrier.
Cancer Patent Description
This application is the U.S. National Phase of International Application
PCT/GB02/03979, filed 30 Aug. 2002, which designated the U.S.
This invention relates to novel anti-cancer agents and more particularly
it relates to cyclopenta[g]quinazoline derivatives which possess
antiproliferative activity.
One group of anti-cancer agents comprises antimetabolites having
antifolate activity, such as the dihydrofolate reductase inhibitor,
methotrexate and the thymidylate synthase (TS) inhibitors CB3717,
raltitrexed and ZD9331. CB3717 is described and claimed in EP-B-0031237,
raltitrexed in EP-B-0239362 and ZD9331 in EP-B-0562734. All of these
TS inhibitors have demonstrable clinical activity in a range of
solid tumours (see Cancer Treatment Reports, 1986, 70, 1335 and
Beale et al., "Tomudex: Clinical Development" in Antifolate
Drugs in Cancer Therapy (ed. Jackman), Humana Press, Totowa, N.J.,
USA, pp. 177-181, 1999). Side-effects of raltitrexed and ZD9331
are predominantly related to inhibition of TS in gut and bone-marrow.
TS catalyses the methylation of deoxyuridine monophosphate to produce
thymidine monophosphate which is required for DNA synthesis. The
anticancer activity of these agents may be assessed in vitro by
determining their inhibitory effect on that enzyme, and in cell
cultures by their inhibitory effect on a range of mouse and human
cancer cell lines (see Boyle et al., "ZD9331: Preclinical and
clinical studies" in Antifolate Drugs in Cancer Therapy (ed.
Jackman), Humana Press, Totowa, N.J., USA, pp. 243-260, 1999 and
Hughes et al., "Raltitrexed (Tomudex), a highly polyglutamatable
antifolate thymidylate synthase inhibitor: design and preclinical
activity" in Antifolate Drugs in Cancer Therapy (ed. Jackman),
Humana Press, Totowa, N.J., USA, pp. 147-165, 1999).
More recently, cyclopenta[g]quinazoline derivatives showing a good
level of activity both as regards their ability to inhibit TS and
also as regards their anticancer activity against various cell lines
have been developed.
WO-A-94/11354 (British Technology Group Limited) discloses tricyclic
compound of formula:
##STR00002## wherein R.sup.1 is hydrogen, amino, C.sub.1-4 alkyl,
C.sub.1-4 alkoxy, C.sub.1-4 hydroxyalkyl or C.sub.1-4 fluoroalkyl;
R.sup.2 is hydrogen, C.sub.1-4 alkyl, C.sub.3-4 alkenyl, C.sub.3-4
alkynyl, C.sub.2-4 hydroxyalkyl, C.sub.2-4 halogenoalkyl or C.sub.1-4
cyanoalkyl;
Ar is phenylene, thiophenediyl, thiazolediyl, pyridinediyl or pyrimidinediyl
which may optionally bear one or two substituents selected from
halogeno, hydroxy, amino, nitro, cyano, trifluoromethyl, C.sub.1-4
alkyl and C.sub.1-4 alkoxy; and
R.sup.3 is a group of one of the following formulae: --NHCH(CO.sub.2H)-A.sup.1-Y.sup.1--NH-A.sup.3-Y.sup.3
or R.sup.3 is a N-linked naturally-occurring amino acid selected
from the group consisting of L-alanine, L-leucine, L-isoleucine,
L-valine and L-phenylalanine. Among the compounds disclosed is the
L-Glu-.gamma.-D-Glu compound CB300638, also mentioned in Clinical
Cancer Research, 5, November 1999 (Supplement) at #566 (Theti et
al.) and Proceedings of the American Association for Cancer Research,
41, March 2000 at #33 (Jackman et al.), as well as in J. Med. Chem.,
2000, 43, 1910-1926, where it is disclosed on page 1923 as compound
7b.
WO-A-95/30673 (British Technology Group Limited) discloses cyclopenta[g]quinazolines
of formula:
##STR00003## wherein R.sup.1 is hydrogen, amino, C.sub.1-4 alkyl,
C.sub.1-4 alkoxy, C.sub.1-4 hydroxyalkyl or C.sub.1-4 fluoroalkyl;
R.sup.2 is hydrogen, C.sub.1-4 alkyl, C.sub.3-4 alkenyl, C.sub.3-4
alkynyl, C.sub.2-4 hydroxyalkyl, C.sub.2-4 halogenoalkyl or C.sub.1-4
cyanoalkyl;
Ar.sup.1 is phenylene, thiophenediyl, thiazolediyl, pyridinediyl
or pyrimidinediyl which may optionally bear one or two substituents
selected from halogeno, hydroxy, amino, nitro, cyano, trifluoromethyl,
C.sub.1-4 alkyl and C.sub.1-4 alkoxy; and
R.sup.3 is a group of one of the following formulae: -A.sup.1-Ar.sup.2-A.sup.2-Y.sup.1-A.sup.5-CON(R)CH(Y.sup.4)Y.sup.5-A.sup.-
8-X--Ar.sup.4
The .alpha.-isoform of the folate receptor (.alpha.-FR; membrane-associated
folate-binding protein) is a glycosylphosphatidylinositol anchored
cell membrane protein that has very high affinity for folic acid
and the more biologically relevant reduced-folates (Kd .about.0.1
nM). The mechanism of folate internalisation is receptor-mediated
endocytosis. The .alpha.-FR is overexpressed in many carcinomas,
particularly those of ovarian origin where it is overexpressed highly
and homogeneously in 90% of cases; see Cancer Res. 51, 5329-5338,
1991 (Campbell et al., 1991). Furthermore, high .alpha.-FR expression
has been linked to aggressive, platinum resistant disease and poor
prognosis--see Int. J. Cancer 74, 193-198, 1997 and Int. J. Cancer
79, 121-126, 1998 (both Toffoli et al.). The .beta.-isoform is widely
expressed in tumours of epithelial and non-epithelial origin with
expression levels being generally low/moderate and high, respectively,
reviewed in Critical Rev. Therap. in Drug Carrier Systems 15, 587-627,
1998 (Reddy and Low).
Folate receptors (.alpha. and .beta.) are expressed in some adult
normal tissues (low to moderate expression). Significant expression
of the .alpha.-FR is largely restricted to kidney proximal tubules
and choroid plexus although it is suggested that it is localised
to the apical membrane surface in these organs and therefore may
not play a significant role in folate uptake from blood (Reddy and
Low, ibid.). There may be a specialised function of the .alpha.-FR
in the proximal tubules of the kidney to salvage folates that escape
in the filtrate.
The .alpha.-FR is hypothesised to be involved in cell signalling
pathways. For example, in IGROV-1 ovarian carcinoma cells, immunoprecipitation
experiments have shown that the .alpha.-FR is associated in membranes
with the G protein G.sub..alpha.1-3, and the non-receptor kinase
lyn.
High FR expression in some tumours relative to normal tissues is
being exploited in several areas of cancer medicine, including the
selective tumour delivery of conjugates of folic acid and toxins,
liposomes, imaging or cytotoxic agents (Reddy and Low, ibid). For
example, folic acid-deferroxamine. .sup.111In conjugates are detected
only in FR-expressing turnouts and not normal tissues of mice, with
the exception of kidney epithelial cells. The high selectivity of
this approach resides in the very low and high affinities of folic
acid (not a major component of plasma) for the RFC (reduced-folate
carrier) and FR respectively. Thus antifolate drugs with similarly
low and high affinity for the RFC and .alpha.-FR respectively could
be highly selective for .alpha.-FR over-expressing tumours relative
to normal tissues. In contrast with the folic acid conjugates they
would not require intracellular cleavage to be active.
We have now discovered that certain compounds within the general
class of cyclopenta[g]quinazolines have an unexpectedly high level
of selectivity for .alpha.-folate receptor expressing human tumour
cell lines. Accordingly the present invention comprises a cyclopenta[g]quinazoline
of formula (I):
##STR00004## wherein:
A is a group OR or NR.sup.0R.sup.1 wherein R.sup.0 and R.sup.1
are each independently hydrogen C.sub.1-4 alkyl, C.sub.3-4 alkenyl,
C.sub.3-4 alkynyl, C.sub.2-4 hydroxyalkyl, C.sub.2-4 halogenoalkyl
or C.sub.1-4 cyanoalkyl, or R.sup.0 and R.sup.1 together with the
intermediate N form a five- or six-membered heterocyclic ring;
p is an integer in the range 1 to 4;
R.sup.2 is hydrogen, C.sub.1-4 alkyl, C.sub.3-4 alkenyl, C.sub.3-4
alkynyl, C.sub.2-4 hydroxyalkyl, C.sub.2-4 halogenoalkyl or C.sub.1-4
cyanoalkyl;
Ar.sup.1 is phenylene, thiophenediyl, thiazolediyl, pyridinediyl
or pyrimidinediyl which may optionally bear one or two substituents
selected from halogeno, hydroxy, amino, nitro, cyano, trifluoromethyl,
C.sub.1-4 alkyl and C.sub.1-4 alkoxy; and
R.sup.3 is a group of the formulae: -A.sup.1-Ar.sup.2-A.sup.2-Y.sup.1
in which A.sup.1 is a bond between the .alpha.-carbon atom of the
group --CO--NH--CH(CO.sub.2H)-- and Ar.sup.2 or is a C.sub.1-2 alkylene
group;
Ar.sup.2 is phenylene, tetrazolediyl, thiophenediyl, thiazolediyl,
pyridinediyl or pyrimidinediyl which in the case of phenylene may
optionally bear one or two substituents on the ring selected from
halogeno, nitro, C.sub.1-4 alkyl and C.sub.1-4 alkoxy;
A.sup.2 is a C.sub.1-3 alkylene or C.sub.2-3 alkenylene group;
and
Y.sup.1 is carboxyl, tetrazol-5-yl, N-(C.sub.1-4 alkylsulfonyl)carbamoyl,
N-(phenylsulfonyl)carbamoyl which may optionally bear one or two
substituents on the phenyl ring selected from the group consisting
of halogeno, nitro, C.sub.1-4 alkyl and C.sub.1-4 alkoxy, tetrazol-5-ylthio,
tetrazol-5-ylsulfinyl or tetrazol-5-ylsulfonyl; or
Y.sup.1 is a group of the formula: --CON(R)CH(Y.sup.2)Y.sup.3
in which R is hydrogen, C.sub.1-4 alkyl, C.sub.3-4 alkenyl or C.sub.3-4
alkynyl;
Y.sup.2 is carboxy, tetrazol-5-yl, N-(C.sub.1-4 alkylsulfonyl)carbamoyl,
N-(phenylsulfonyl)carbamoyl which may optionally bear one or two
substituents on the phenyl ring selected from the group consisting
of halogeno, nitro, C.sub.1-4 alkyl and C.sub.1-4 alkoxy, tetrazol-5-ylthio,
tetrazol-5-ylsulfinyl or tetrazol-5-ylsulfonyl; and
Y.sup.3 is the residue of a naturally occurring amino acid NH.sub.2CH(CO.sub.2H)Y.sup.3;
or
Y.sup.3 is a group of the formula: -A.sup.4-CO.sub.2H
in which A.sup.4 is a C.sub.2-6 alkylene group;
R.sup.3 is a group of the formula: -A.sup.5-CON(R)CH(Y.sup.4)Y.sup.5
in which A.sup.5 is a C.sub.1-6 alkylene group and R is as defined
above;
Y.sup.4 is carboxy, tetrazol-5-yl, N-(C.sub.1-4 alkylsulfonyl)carbamoyl,
N-(phenylsulfonyl)carbamoyl which may optionally bear one or two
substituents on the phenyl ring selected from the group consisting
of halogeno, nitro, C.sub.1-4 alkyl and C.sub.1-4 alkoxy, tetrazol-5-ylthio,
tetrazol-5-ylsulfinyl or tetrazol-5-ylsulfonyl; and
Y.sup.5 is the residue of a naturally occurring amino acid NH.sub.2CH(CO.sub.2H)Y.sup.5;
or
Y.sup.5 is a group of the formula: -A.sup.4-CO.sub.2H
in which A.sup.4 is as defined above; or
Y.sup.5 is a group of the formula: -A.sup.6-Ar.sup.3-A.sup.7-Y.sup.6
in which A.sup.6 is a bond between the .alpha.-carbon atom of the
group -A.sup.5-CON(R)CH(Y.sup.4)-- and Ar.sup.3 or is a C.sub.1-2
alkylene group;
Ar.sup.3 is phenylene, tetrazolediyl, thiophenediyl, thiazolediyl,
pyridinediyl or pyrimidinediyl which in the case of phenylene may
optionally bear one or two substituents on the ring selected from
halogeno, nitro, C.sub.1-4 alkyl and C.sub.1-4 alkoxy;
A.sup.7 is a C.sub.1-3 alkylene or C.sub.2-3 alkenylene group;
and
Y.sup.6 is carboxy, tetrazol-5-yl, N-(C.sub.1-4 alkylsulfonyl)carbamoyl,
N-(phenylsulfonyl)carbamoyl which may optionally bear one or two
substituents on the phenyl ring selected from the group consisting
of halogeno, nitro, C.sub.1-4 alkyl and C.sub.1-4 alkoxy, tetrazol-5-ylthio,
tetrazol-5-ylsulfinyl or tetrazol-5-ylsulfonyl; or
R.sup.3 is a group of the formula: -A.sup.8-X--Ar.sup.4
in which A.sup.8 is a C.sub.1-4 alkylene group;
X is sulfinyl, sulfonyl or methylene; and
Ar.sup.4 is 1,2,3-triazol-4-yl, 1,2,4-triazol-3-yl or, except when
X is methylene, tetrazol-5-yl;
the compound (I) optionally being in the form of a pharmaceutically
acceptable salt or ester.
In this specification the terms alkyl, alkenyl, alkynyl and alkylene
include both straight and branched chain groups but references to
individual alkyl or alkylene groups, such as "propyl",
are specific for the straight chain group only. An analogous convention
applies to other generic terms. Moreover, the numbering system used
for the cyclopenta[g]quinazoline nucleus is the conventional one
as shown below:
##STR00005##
Amino-acid residues are designated herein in the standard manner
(Pure and Applied Chemistry, 1974, 40, 317 and European Journal
of Biochemistry, 1984, 138, 9). Thus, for example, 7-glutamyl denotes
the radical H.sub.2NCH(CO.sub.2H)CH.sub.2CH.sub.2CO-- or --NHCH(CO.sub.2H)CH.sub.2CH.sub.2CO--
according to the context, the carbon atoms in these radicals being
numbered from the carbon atom of the .alpha.-carboxy group as position
1.
It will be observed that a cyclopenta[g]quinazoline of the invention
contains at least two asymmetric carbon atoms [present at the point
of attachment of the group --N(R.sup.2)-- to the tricyclic ring
system and at the .alpha.-carbon atom of the group --CONHCH(CO.sub.2H)--]
and can therefore exist in racemic and optically active forms. It
is to be understood that this invention encompasses both racemic
and optically active forms of the physiologically active cyclopenta[g]quinazolines,
it being a matter of common general knowledge how such optically
active forms may be obtained by stereospecific synthesis or by separation
of a mixture of isomeric compounds. It will be appreciated that
one isomer may be of more interest than another due to the nature
of the activity which it exhibits or due to superior physical properties,
for example aqueous solubility.
It is also to be understood that a cyclopenta[g]quinazoline of
the formula (I) may exhibit the phenomenon of tautomerism and that
the formulae shown in this specification represent only one of the
possible tautomeric forms. Moreover, it will be appreciated that
when, for example, Y.sup.1, Y.sup.2, Y.sup.4 or Y.sup.6 is a tetrazol-5-yl
group, that group may be in the form of a 1H-tetrazol-5-yl group
or a 2H-tetrazol-5-yl group. It is to be understood therefore that
the invention is not limited merely to any one tautomeric form which
is illustrated.
It is also to be understood that certain cyclopenta[g]quinazolines
of the formula (I) can exist in solvated as well as unsolvated forms
such as, for example, hydrated forms.
A suitable value for R.sup.0, R.sup.1 or R.sup.2 when it is C.sub.1-4
alkyl, or for a C.sub.1-4 alkyl substituent which may be present
on Ar.sup.1, Ar.sup.2 or Ar.sup.3 or on a phenyl group-containing
group Y.sup.1, Y.sup.2, Y.sup.4 or Y.sup.6 present in R.sup.3, or
for a group R present in R.sup.3 when it is C.sub.1-4 alkyl, is,
for example, methyl, ethyl, propyl or isopropyl.
A suitable value for a C.sub.1-4 alkoxy substituent which may be
present on Ar.sup.1, Ar.sup.2 or Ar.sup.3 or on a phenyl-containing
group Y.sup.1, Y.sup.2, Y.sup.4 or Y.sup.6 is, for example, methoxy,
ethoxy, propoxy, isopropoxy or butoxy.
A suitable value for a halogeno substituent which may be present
on Ar.sup.1, Ar.sup.2 or Ar.sup.3 or on a phenyl-containing group
Y.sup.1, Y.sup.2, Y.sup.4 or Y.sup.6 is, for example, fluoro, chloro
or bromo.
A suitable value for R.sup.0, R.sup.1 and R.sup.2 when it is C.sub.3-4
alkenyl or for a group R present in R.sup.3 when it is alkenyl,
is, for example, prop-2-enyl, but-2-enyl, but-3-enyl or 2-methylprop-2-enyl;
and when it is C.sub.3-4 alkynyl is, for example, prop-2-ynyl or
but-3-ynyl.
A suitable value for R.sup.0, R.sup.1 and R.sup.2 when it is C.sub.2-4
hydroxyalkyl is, for example, 2-hydroxyethyl or 3-hydroxypropyl;
when it is C.sub.2-4 halogenoalkyl is, for example, 2-fluoroethyl,
2-chloroethyl, 2-bromoethyl, 3-fluoropropyl, 3-chloropropyl or 3-bromopropyl;
and when it is C.sub.1-4 cyanoalkyl is, for example, cyanomethyl,
2-cyanoethyl or 3-cyanopropyl.
When R.sup.0 and R.sup.1 together with the intermediate N form
a five- or six-membered heterocyclic ring, this may bear substituents,
but the ring is preferably an unsubstituted saturated ring such
as pyrrolidine or piperidine.
A suitable value for Ar.sup.1, A.sup.2 or Ar.sup.3 when it is phenylene
is, for example, 1,3- or 1,4-phenylene, especially 1,4-phenylene.
A suitable value for Ar.sup.1, Ar.sup.2 or Ar.sup.3 when it is
thiophenediyl is, for example, thiophene-2,4-diyl or thiophene-2,5-diyl;
when it is thiazolediyl is, for example thiazole-2,4-diyl or thiazole-2,5-diyl;
when it is pyridinediyl is, for example, pyridine-2,4-diyl, pyridine-2,5-diyl,
pyridine-2,6-diyl or pyridine-3,5-diyl; and when it is pyrimidinediyl
is, for example, pyrimidine-2,4-diyl, pyrimidine-2,5-diyl or pyrimidine-4,6-diyl.
As indicated, Ar.sup.1 and a phenylene group Ar.sup.2 or Ar.sup.3
or a phenyl group in Y.sup.1 may carry one or two substituents.
A preferred level of substitution in Ar.sup.1, where substitution
is present, is either two substituents or especially one substituent;
and the one or two substituents may conveniently be at positions
adjacent to the atom bonded to the group --CONHCH(CO.sub.2H)--R.sup.3,
halogeno substituents such as fluoro being preferred. A preferred
level of substitution on a phenylene group Ar.sup.2 or Ar.sup.3
or on a phenyl group in Y.sup.1, where substitution is present,
is one substituent.
When R.sup.3 is a group of the formula: -A.sup.1-Ar.sup.2-A.sup.2-Y.sup.1
a suitable value for A.sup.1 when it is a C.sub.1-2 alkylene group
is, for example methylene or ethylene and for A.sup.2 when it is
a C.sub.1-3 alkylene group is, for example, methylene, ethylene
or trimethylene. A suitable value for A.sup.2 when it is a C.sub.2-3
alkenylene group is, for example, vinylene or especially propenylene
(--CH.sub.2CH.dbd.CH-- or --CH.dbd.CH(CH.sub.2--). A preferred value
for both A.sup.1, when it is not a bond, and for A.sup.2 is methylene
or ethylene. Suitable values for Ar.sup.2 include those which have
been discussed hereinbefore, such as thiophenediyl or most especially
phenylene, or additionally tetrazole-1,5-diyl or tetrazole-2,5-diyl.
A suitable value for Y.sup.1 or for Y.sup.2 in a group Y.sup.1 of
formula --CON(R)CH(Y.sup.2)Y.sup.3 when it is N-(C.sub.1-4 alkylsulfonyl)carbamoyl
is, for example, N-methylsulfonylcarbamoyl, N-ethylsulfonylcarbamoyl
or N-propylsulfonylcarbamoyl.
In a group Y.sup.1 of formula --CON(R)CH(Y.sup.2)Y.sup.3 suitable
values for C.sub.1-4 alkyl, C.sub.3-4 alkenyl and C.sub.3-4 alkynyl
groups R have been discussed hereinbefore but R is preferably either
methyl or especially hydrogen; a suitable value for Y.sup.3 when
it is the residue of a naturally occurring amino acid is the residue
of alanine (Y.sup.3=CH.sub.3), arginine (Y.sup.3=(CH.sub.2).sub.3NHC(H.sub.2).dbd.NH),
aspartic acid (Y.sup.3=CH.sub.2CO.sub.2H), cysteine (Y.sup.3=CH.sub.2SH),
isoleucine (Y.sup.3=CH(CH.sub.3)CH.sub.2CH.sub.3), leucine (Y.sup.3=CH.sub.2CH(CH.sub.3)CH.sub.3),
ornthine (Y.sup.3=(CH.sub.2).sub.3NH.sub.2), phenylalanine (Y.sup.3=CH.sub.2C.sub.6H.sub.5),
serine (Y.sup.3=CH.sub.2OH) and valine (Y.sup.3=CH(CH.sub.3).sub.2)
and especially glutamic acid (Y.sup.3=CH.sub.2CH.sub.2CO.sub.2H).
A suitable value for A.sup.4 when Y.sup.3 is a group of the formula
-A.sup.4-CO.sub.2H is trimethylene, pentamethylene or hexamethylene,
A.sup.4 preferably being a C.sub.3-6 alkylene group with especially
suitable values for Y.sup.3 being --(CH.sub.2).sub.nCO.sub.2H where
n is 3, 4 or 5.
A preferred value for Y.sup.1 or for Y.sup.2, Y.sup.4 and Y.sup.6,
is tetrazol-5-yl or especially carboxy.
When R.sup.3 is a group of the formula: -A.sup.5-CON(R)CH(Y.sup.4)Y.sup.5
a suitable value for A.sup.5 is, for example, methylene, ethylene,
trimethylene, tetramethylene, pentamethylene or hexamethylene and
a suitable value for R is as described hereinbefore. A suitable
value for Y.sup.4 when it is N-(C.sub.1-4 alkylsulfonyl)-carbamoyl
is, for example, N-methylsulfonylcarbamoyl, N-ethylsulfonylcarbamoyl
or N-propylsulfonylcarbamoyl.
A suitable value for Y.sup.5 when it is the residue of a naturally
occurring amino acid is alanine (Y.sup.5=CH.sub.3), arginine (Y.sup.5=(CH.sub.2).sub.3NHC(NH.sub.2).dbd.NH),
aspartic acid (Y.sup.5=CH.sub.2CO.sub.2H), cysteine (Y.sup.5=CH.sub.2SH),
isoleucine (Y.sup.5=CH(CH.sub.3)CH.sub.2CH.sub.3), leucine (Y.sup.5=CH.sub.2CH(CH.sub.3)CH.sub.3),
ornithine (Y.sup.5=(CH.sub.2).sub.3NH.sub.2), phenylalanine (Y.sup.5=CH.sub.2C.sub.6H.sub.5),
serine (Y.sup.5=CH.sub.2OH), valine (Y.sup.5=CH(CH.sub.3).sub.2),
and especially glutamic acid (Y.sup.5=CH.sub.2CH.sub.2CO.sub.2H).
When Y.sup.5 is a group of the formula -A.sup.4-CO.sub.2H, suitable
values for A.sup.4 and Y.sup.5 are as described hereinbefore in
relation to a group Y.sup.3 of the formula -A.sup.6-CO.sub.2H.
A suitable value for A.sup.6 in a group Y.sup.5 of the formula
-A.sup.6-Ar.sup.3-A.sup.7-Y.sup.6 is as described hereinbefore for
A.sup.1 and for A.sup.7 is as described for A.sup.2. A suitable
value for Ar.sup.3 is as described hereinbefore for Ar.sup.2. A
suitable value for Y.sup.6 in such a group Y.sup.5 when it is N-(C.sub.1-4
alkylsulfonyl)carbamoyl is, for example, N-methylsulfonylcarbamoyl,
N-ethylsulfonylcarbamoyl or N-propylsulfonylcarbamoyl.
When R.sup.3 is a group of the formula: -A.sup.8-X--Ar.sup.4
a suitable value for A.sup.8 is, for example, methylene, ethylene,
trimethylene or tetramethylene.
Groups R.sup.3 of particular value have the formula -A.sup.1-Ar.sup.2-A.sup.2-Y.sup.1,
especially when Y.sup.1 is a group not of the formula --CON(R)CH(Y.sup.2)Y.sup.3,
such as carboxy or tetrazol-5-yl.
Specific examples of such groups R.sup.3 are groups -A.sup.1-Ar.sup.2-A.sup.2-Y.sup.1
in which A.sup.1 is a bond or methylene or ethylene, Ar.sup.2 is
phenylene, thiophenediyl or tetrazolediyl, A.sup.2 is methylene,
ethylene or trimethylene and Y.sup.1 is carboxy or tetrazol-5-yl.
Other groups R.sup.3 of particular value have the formula -A.sup.5-CON(R)CH(Y.sup.4)Y.sup.5,
especially when Y.sup.5 is a group of the formula -A.sup.6-Ar.sup.3-A.sup.7-Y.sup.6
in which Ar.sup.3 is phenylene, thiophenediyl or tetrazolediyl.
Specific examples of such groups R.sup.3 are groups -A.sup.5-CON(R)CH(Y.sup.4)-A.sup.6-Ar.sup.3-A.sup.7-Y.sup.6
in which A.sup.5 is methylene or ethylene, R is hydrogen or methyl,
Y.sup.4 is carboxy or tetrazol-5-yl, A.sup.6 is a bond or is methylene
or ethylene, Ar.sup.3 is phenylene, thiophenediyl or tetrazolediyl,
A.sup.7 is methylene, ethylene or trimethylene and Y.sup.6 is carboxy
or tetrazol-5-yl.
A suitable pharmaceutically-acceptable salt form of a cyclopenta[g]quinazoline
of the invention is, for example, an acid addition salt with an
inorganic or organic acid, for example hydrochloric, hydrobromic,
trifluoroacetic or maleic acid; or an alkali metal, for example
sodium, an alkaline earth metal, for example calcium, or ammonium,
for example tetra(2-hydroxyethyl)ammonium, salt.
A suitable pharmaceutically-acceptable ester form of a cyclopenta[g]quinazoline
of the invention is, for example, an ester with an aliphatic alcohol
of up to 6 carbon atoms, for example a methyl, ethyl or tert-butyl
ester.
It is to be understood that R.sup.3 may contain several carboxy
groups in addition to the carboxy group in the grouping --CONHCH(CO.sub.2H)--.
When, for example, two carboxy groups are present in the cyclopenta[g]quinazoline,
a salt or ester may be mono-acid-mono-salt or -ester, -di-salt or
di-ester and when, for example, three carboxy groups are present
a salt or ester may be mono-acid-di-salt or -ester, di-acid-mono-salt
or -ester or even tri-salt or -ester.
Particularly preferred values for the various symbols R.sup.0,
R.sup.1, R.sup.2 and Ar.sup.1 individually are as expressed for
the preferred cyclopenta[g]quinazolines described hereinafter.
A preferred cyclopenta[g]quinazoline of the invention has the formula
(I) wherein R.sup.0 and R.sup.1 are each independently hydrogen
or C.sub.1-4 alkyl, especially methyl;
wherein R.sup.2 is ethyl, propyl, prop-2-enyl, prop-2-ynyl, 2-hydroxyethyl,
2-fluoroethyl, 2-bromoethyl or 2-cyanoethyl;
wherein Ar.sup.1 is 1,4-phenylene which may optionally bear one
or two substituents selected from the group consisting of chloro
and especially fluoro, thiophene-2,5-diyl, thiazole-2,5-diyl or
pyridine-2,5-diyl;
wherein R.sup.3 is a group of the formula -A.sup.1-Ar.sup.2-A.sup.2-Y.sup.1
in which A.sup.1 is a bond or is methylene or ethylene, Ar.sup.2
is phenylene, A.sup.2 is methylene, ethylene or trimethylene and
Y.sup.1 is a group of the formula: --CON(R)CH(Y.sup.2)Y.sup.3
in which R is hydrogen, C.sub.1-4 alkyl, C.sub.3-4 alkenyl or C.sub.3-4
alkynyl;
Y.sup.2 is carboxy, tetrazol-5-yl, N-(C.sub.1-4 alkylsulfonyl)carbamoyl,
N-(phenylsulfonyl)carbamoyl which may optionally bear one or two
substituents on the phenyl ring selected from the group consisting
of halogeno, nitro, C.sub.1-4 alkyl and C.sub.1-4 alkoxy, tetrazol-5-ylthio,
tetrazol-5-ylsulfinyl or tetrazol-5-ylsulfonyl; and
Y.sup.3 is the residue of a naturally occurring amino acid NH.sub.2CH(CO.sub.2H)Y.sup.3.
Alternatively, a preferred cyclopenta[g]quinazoline of the invention
has the formula (I) wherein:
R.sup.0 and R.sup.1 are each independently hydrogen or C.sub.1-4
alkyl;
R.sup.2 is ethyl, propyl, prop-2-enyl, prop-2-ynyl, 2-hydroxyethyl,
2-fluoroethyl, 2-bromoethyl or 2-cyanoethyl;
Ar.sup.1 is 1,4-phenylene which may optionally bear one or two
substituents selected from the group consisting of chloro, fluoro,
thiophene-2,5-diyl, thiazole-2,5-diyl or pyridine-2,5-diyl;
R.sup.3 is a group of the formula: -A.sup.5-CON(R)CH(Y.sup.4)Y.sup.5
in which A.sup.5 is a C.sub.1-6 alkylene group and R is as defined
above;
Y.sup.4 is carboxy, tetrazol-5-yl, N-(C.sub.1-4 alkylsulfonyl)carbamoyl,
N-(phenylsulfonyl)carbamoyl which may optionally bear one or two
substituents on the phenyl ring selected from the group consisting
of halogeno, nitro, C.sub.1-4 alkyl and C.sub.1-4 alkoxy, tetrazol-5-ylthio,
tetrazol-5-ylsulfinyl or tetrazol-5-ylsulfonyl; and
Y.sup.5 is the residue of a naturally occurring amino acid NH.sub.2CH(CO.sub.2H)Y.sup.5.
A preferred value for p is 1.
A further preferred cyclopenta[g]quinazoline of the invention has
the formula (I) wherein A is a group OR.sup.0 in which R.sup.0 is
hydrogen or methyl;
wherein R.sup.2 is ethyl or prop-2-ynyl; and
wherein Ar.sup.1 is 1,4-phenylene or 1,4-phenylene having a 2-fluoro
substituent as in 2,6-difluoro-1,4-phenylene or especially 2-fluoro-1,4-phenylene
or is pyridine 2,5-diyl; and
R.sup.3 is as just described above.
An especially preferred cyclopenta[g]quinazoline of the invention
has the formula (I) wherein A is a group OR.sup.0 in which R.sup.0
is hydrogen or methyl;
wherein R.sup.2 is ethyl or preferably prop-2-ynyl;
wherein Ar.sup.1 is 1,4-phenylene or 2-fluoro-1,4-phenylene; and
wherein R.sup.3 is the residue of an acid NH.sub.2. CH(COOH)R.sup.3
which comprises L-Glu-.gamma.-D-Glu, i.e. N-L-.gamma.-glutamyl-D-glutamic
acid.
Other quinazolines of the invention of particular interest have
the values of R.sup.0, R.sup.1, R.sup.2, and Ar.sup.1 and Ar in
combination as indicated above but with R.sup.3 having any value
as indicated hereinbefore. However, specific particularly preferred
cyclopenta[g]quinazolines of the invention are:
N-{N-{4-[N-((6RS)-2-methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g-
]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-D-glut-
amic acid;
N-{N-{4-[N-((6RS)-2-hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g-
]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-D-glut-
amic acid; and
N-{N-{4-[N-((6RS)-2-hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g-
]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-N-meth-
yl-L-glutamic acid;
or a pharmaceutically acceptable salt or ester thereof.
Although the compounds of the present invention can exist as a
mixture of stereoisomers it is preferred that they are resolved
into one optically active isomeric form. Such a requirement complicates
the synthesis of the compounds and it is preferred therefore that
they contain as few asymmetric carbon atoms as possible consistent
with achieving the desired activity.
As indicated previously, however, the cyclopenta[g]quinazolines
of the present invention contain at least two asymmetric carbon
atoms. Of these, that at the 6 position of the ring system preferably
has the 6S orientation rather than the 6R orientation, whilst the
alpha carbon atom of the group --CONHCH(CO.sub.2H)-- preferably
has the L rather than the D configuration. The preferred compounds
(I) described hereinbefore thus preferably have such a configuration
at these two asymmetric carbon atoms or less preferably are a racemic
mixture in which one or both of these asymmetric carbon atoms is
unresolved.
The asymmetric carbon atom of a residue R.sup.3 of the form -A.sup.1-Ar.sup.2-A.sup.2-CON(R)CH(Y.sup.2)Y.sup.3
or -A.sup.5-CON(R)CH(Y.sup.4)Y.sup.5 may be of the L- or D-configuration
but the amide bond will be stabilised in vivo when it is of the
D-configuration as it will also be when R is other than hydrogen.
When Y.sup.3 or Y.sup.5 is the residue of a naturally occurring
amino acid, however, the amino acid intermediate for the synthesis
of the cyclopenta[g]quinazoline will of course be more readily available
when this asymmetric carbon atom is of the L-configuration.
A cyclopenta[g]quinazoline of the invention may be prepared by
any process known to be applicable to the preparation of chemically-related
compounds.
As stated above, cyclopenta[g]quinazolincs of the present invention
are believed to function as anti-cancer agents at least in part
due to their ability to inhibit the enzyme thymidylate synthase.
This anti-cancer activity may be assessed, for example, using one
or more of the procedures set out below:
(a) An in vitro assay which determines the ability of a test compound
to inhibit the enzyme thymidylate synthase. Thymidylate synthase
may be obtained in partially purified form from L1210 mouse leukemia
cells and utilised in the assay using the procedures described by
Jackman et al. (Cancer Res., 1986, 46, 2810) and Sikora et al. (Biochem.
Pharmacol., 1988, 37, 4047);
(b) An assay which determines the ability of a test compound to
bind to the .alpha.-FR relative to that of folic acid, using mouse
L1210-FBP cells (.alpha.-FR expression) in the procedure described
by Westerhof et al. (Cancer Res., 1991, 51, 5507-5513);
(c) An assay which determines the ability of a test compound to
inhibit the growth of human tumour cell lines expressing the .alpha.-FR
(A431-FBP vulvular carcinoma transfected with the .alpha.-FR; KB
nasopharengeal carcinoma);
(d) An assay which determines the ability of a test compound to
inhibit the growth of human tumour cell lines not expressing the
.alpha.-FR (A431 neo-transfected);
(e) An assay confirming or demonstrating that compound-induced
growth inhibition is largely attributable to .alpha.-FR mediated
uptake into KB or A431-FBP cells. This involves the co-addition
of an excess of folic acid (1 .mu.M) to compete with the compounds
for FR but not RFC binding.
Although the pharmacological properties of the cyclopenta[g]quinazolines
of the invention depend on their detailed structure, in general
the cyclopenta[g]quinazolines of the invention possess activity
in one or more of the above tests (a) to (d) as indicated below:
TABLE-US-00001 Test (a) IC.sub.50 in the range, for example, 0.0001-1
.mu.M; Test (b) Inverse relative affinity in the range, for example,
0.05-5 (values geater than 1 implies binding is greater than that
of folic acid and values less that 1 implies binding weaker than
that of folic acid); Test (c) IC.sub.50 in the range, for example,
0.001-10 .mu.M; Test (d) IC.sub.50 in the range, for example, 0.01-100
.mu.M; Test (e) IC.sub.50 at least 10-fold higher than that seen
in test (b) for the same cell line.
A cyclopenta[g]quinazoline of the present invention may itself
be active or it may be a pro-drug which is converted in vivo to
an active compound. A cyclopenta[g]quinazoline of the invention
may be administered to a warm-blooded animal, including a human,
in the form of a pharmaceutical composition which comprises the
cyclopenta[g]quinazoline in association with a pharmaceutically-acceptable
diluent or carrier.
The composition may be in a form suitable for oral use, for example
a tablet, capsule, aqueous or oily solution, suspension or emulsion;
a form suitable for topical use, for example a cream, ointment,
gel or aqueous or oily solution or suspension; a form suitable for
nasal use, for example a snuff, nasal spray or nasal drops; a form
suitable for vaginal or rectal use, for example a suppository; a
form suitable for administration by inhalation, for example as a
finely divided powder such as a dry powder, a microcrystalline form
or a liquid aerosol; a form suitable for sub-lingual or buccal use,
for example a tablet or capsule; or a form suitable for parenteral
use (including intravenous, subcutaneous, intramuscular, intravascular
or infusion use), for example a sterile aqueous or oily solution,
emulsion or suspension. In general the above compositions may be
prepared in a conventional manner using conventional excipients.
The composition may contain, in addition to the cyclopenta[g]quinazoline
of the invention, one or more other anti-cancer substances selected
from, for example, other antimetabolites, DNA interacting agents,
signal transduction inhibitors or other inhibitors of deregulated
pathways in tumours.
The cyclopenta[g]quinazoline will normally be administered to a
warm-blooded animal at a dose within a range of 50-25000, particularly
50-5000, mg per square metre body area of the animal, i.e. approximately
1500, particularly 1-100, mg/kg. Where desired, however, dosages
outside this range may be employed and, in particular, where the
preferred mode of administration involving subcutaneous infusion
is used then the does range may be increased to 1-1000 mg/kg. Preferably
a daily dose in the range 10-250 mg/kg is employed, particularly
30-150 mg/kg. However, the daily dose will necessarily be varied
depending upon the host treated, the particular route of administration
and the severity of the illness being treated. Accordingly, the
optimum dosage may be determined by the practitioner who is treating
any particular patient.
Accordingly the present invention also includes a method for aiding
regression and palliation of cancer in a patient, particularly a
warm-blooded animal such as a human, in need of such treatment,
which comprises administering to said patient an effective amount
of a cyclopenta[g]quinazoline as defined hereinbefore. The invention
also provides the use of such a cyclopenta[g]quinazoline in the
manufacture of a novel medicament for use in the treatment of cancer.
Cyclopenta[g]quinazolines of the present invention are of interest
for a wide range of anti-tumour activities particularly the treatment
of ovarian cancer.
In view of the activity shown by antimetabolites such as aminopterin
and methotrexate, which is discussed hereinbefore, the cyclopenta[g]quinazolines
of the present invention are also of interest for use in the treatment
of other conditions, for example allergic conditions such as psoriasis
and inflammatory diseases such as rheumatoid arthritis. In using
a cyclopenta[g]quinazoline of the invention for such a purpose the
compound will normally be administered at a dose within the range
5-25000, particularly 5-500, mg per square metre body area of the
animal, i.e. approximately 0.1-500, particularly 0.1-10, mg/kg.
Where desired, however, dosages outside this range may be employed.
In general, for the treatment of an allergic condition such as psoriasis,
topical administration of a cyclopenta[g]quinazoline of the invention
is preferred. Thus, for example, for topical administration a daily
dose in the range, for example, of 0.1 to 10 mg/kg may be used.
Compositions containing the quinazolines may be formulated in unit
dosage form, i.e. in the form of discrete portions each comprising
a unit dose, or a multiple or sub-multiple of a unit dose, for example
as a tablet or capsule. Such a unit dosage form may, for example,
contain an amount of the cyclopenta[g]quinazoline in the range of
1-250 or 1-500 mg.
The invention is illustrated by the following Examples.
EXAMPLE 1
Synthesis of CB300951 (2-CH.sub.2OMe Derivative of CB300638)
##STR00006##
5-Methoxyacetamidoindan
To a solution of 5-aminoindan (4.66 g, 35.0 mmol) in anhydrous
DMF (26 ml) was slowly added methoxyacetyl chloride (5.70 g, 52.50
mmol) followed by pyridine (8.5 ml, 105.0 mmol). The red solution
was stirred at room temperature for 3.5 hours under argon, then
it was partitioned between ethyl acetate (200 ml) and 1N HCl (120
ml). The organic layer was washed with more 1N HCl (120 ml), brine
(100 ml), dried (Na.sub.2SO.sub.4) and concentrated in vacuo. The
residue was triturated with diethyl ether; the white precipitate
was collected by filtration, washed with diethyl ether to afford
the title compound (5.93 g, 83%), m.p. 104-105.degree. C.; .sup.1H-NMR
(250 MHz, CDCl.sub.3, TMS) 2.06 (m, 2H, 2-CH.sub.2), 2.87 (m, 4H,
1-CH.sub.2 and 3-CH.sub.2), 3.50 (s, 3H, OCH.sub.3), 4.00 (s, 2H,
2-CH.sub.2OMe), 7.22 (m (overlap with CHCl.sub.3 peak), 2H, 6-H,
7-H), 7.52 (s, 1H, 4-H), 8.18 (s, 1H, CONH); MS (ESI, m/z): 432
[(2M+Na).sup.+, 30%], 206[(M+H).sup.+, 100%]; Found C, 70.10; H,
7.38; N, 6.81; C.sub.12H.sub.15NO.sub.2 requires C, 70.22; H, 7.37;
N, 6.82%.
5-Methoxyacetamido-6-bromoindan
A mixture of 5-methoxyacetamidoindan (5.50 g, 0.027 mol) and glacial
acetic acid (25 ml) was cooled in an ice-water bath (.about.10.degree.
C.). Bromine (1.5 ml, 0.029 mol) was then dropwise added over a
20 min period while the temperature was kept between 10-15.degree.
C. The reaction mixture was then stirred for a longer 1 hour and
then it was poured into an ice-water bath (100 ml) with the aid
of water (70 ml). The precipitate was collected by filtration, washed
with plenty of water (150 ml) and dried in vacuo over P.sub.2O.sub.5
to afford the title compound (6.98 g, 91%), m.p. 84-86.degree. C.;
.sup.1H-NMR (250 MHz, CDCl.sub.3, TMS) 2.09 (m, 2H, 2-CH.sub.2),
2.88 (m, 4H, 1-CH.sub.2 and 3-CH.sub.2), 3.55 (s, 3H, OCH.sub.3),
4.04 (s, 2H, 2-CH.sub.2OMe), 7.34, 8.22 (2.times.s, 2H, 4-H, 7-H),
8.83 (s, 1H, CONH);
MS (ESI, m/z): 284, 286 [(M+H).sup.+, 98%, 100%; Br isotopic pattern];
Found C, 50.62; H, 4.93; N, 4.92; Br, 28.05; C.sub.12H.sub.14BrNO.sub.2
requires C, 50.72; H, 4.97; N, 4.93; Br, 28.12%.
5-Methoxyacetamido-6-bromoindan-1-one
To a solution of 5-methoxyacetamido-6-bromoindan (0.85 g, 3.0 mmol)
in glacial acetic acid (7 ml) heated at 55.degree. C. was dropwise
added a solution of CrO.sub.3 (1.2 g, 12.0 mmol) in aqueous glacial
acetic acid, (7 ml, v/v 1:1) over a 15 min period. The reaction
mixture was then stirred at this temperature for 45 min. The reaction
mixture was cooled in an ice-bath, then propan-2-ol (4 ml) was added
and the mixture was stirred at this temperature for 10 min before
being concentrated in vacuo. The black residue was broken up with
a spatula with the aid of water and then partitioned between water
(50 ml) and ethyl-acetate (150 ml). The aqueous layer was extracted
with more ethyl acetate (2.times.40 ml), the combined extracts were
dried (Na.sub.2SO.sub.4), and concentrated in vacuo to give an off
white residue. Purification by column chromatography on elution
with 5% ethyl acetate in dichloromethane afforded in order of elution:
a. 5-methoxyacetamido-6-bromoindan-1-one as a white solid which
was further purified by trituration with ethyl acetate/hexanes (1:5,
v/v): 0.50 g (55%),
m.p. 162-163.degree. C.; .sup.1H-NMR (250 MHz, CDCl.sub.3, TMS)
2.72 (m, 2H, 2-CH.sub.2), 3.11 (m, 2H, 3-CH.sub.2), 3.57 (s, 3H,
OCH.sub.3), 4.09 (s, 2H, 2-CH.sub.2OMe), 7.95 (s, 1H) and 8.65 (s,
1H) (2H, 4-H, 7-H), 9.27 (s, 1H, CONH); MS (ESI, m/z) 298, 300 {(M+H).sup.+,
100%, 97% respectively, bromine isotopic pattern}; Found: C, 48.13;
H, 3.99; N, 4.70; Br, 26.95; C.sub.12H.sub.12BrNO.sub.3 requires
C, 48.34; H, 4.06; N, 4.70; Br, 26.80%); and
b. 5-acetamido-6-bromoindan-3-one as a solid which was further
purified by trituration with ethyl acetate/hexanes (1:5, v/v): 0.026
g, (3%), m.p. 149-151.degree. C.
.sup.1H-NMR (250 MHz, CDCl.sub.3, TMS) 2.71 (m, 2H, 2-CH.sub.2),
3.01 (m, 2H, 1-CH.sub.2), 3.56 (s, 3H, OCH.sub.3), 4.08 (s, 2H,
2-CH.sub.2OMe), 7.73 (s, 1H) and 8.71 (s, 1H) (2H, 4-H, 7-H), 8.97
(s, 1H, CONH); MS (ESI, m/z) 298, 300 {(M+H).sup.+, 100%, 98% respectively,
bromine isotopic pattern}; Found: C, 47.95; H, 3.96; N, 4.59; Br,
26.63; C.sub.12H.sub.12BrNO.sub.3 requires C, 48.34; H, 4.06; N,
4.70; Br, 26.80%).
tert-Butyl 4-[N-(5-methoxyacetamido-6-bromoindan-1-yl)amino]benzoate
Method A: To a flask containing 5-methoxyacetamido-6-bromoindan-1-one
(0.357 g, 1.2 mmol), 4-toluenesulfonic acid monohydrate (0.015 g),
and tert-butyl 4-aminobenzoate (0.289 g, 1.5 mmol) was added 1,2-dimethoxyethane
(dried by distillation over CaH.sub.2; 15 ml). An Aldrich azeotropic
distillation apparatus containing molecular sieves (3A) was fitted
to the reaction flask that was placed in an oil bath preheated to
115.degree. C. The reaction mixture was stirred at this temperature
for 3.5 hours under argon; then allowed to cool to room temperature,
and a solution of sodium cyanoborohydride in tetrahydrofuran (1M;
1.55 ml, 1.55 mmol) was added followed immediately by acetic acid
(0.044 ml). The black reaction mixture was stirred at room temperature
for 1 hour under argon; then it was partitioned between ethyl acetate
(150 ml) and saturated aqueous sodium bicarbonate (100 ml). The
aqueous layer was extracted with more ethyl acetate (100 ml); the
organic extracts were combined, washed with brine (100 ml), dried
(Na.sub.2SO.sub.4), and concentrated in vacuo to leave a reddish
residue. Purification by column chromatography, on elution with
35% ethyl acetate in petroleum ether (60-80.degree. C.), afforded
the desired product as a white solid: 0.175 g (31%).
Method B. To a nearly clear solution of 5-methoxyacetamido-6-bromoindan-1-one
(0.300 g, 1.0 mmol) in anhydrous methanol (40 ml) was added tert-butyl
4-aminobenzoate (0.193 g, 1.0 mmol) followed by decaborane (0.044
g). The reaction mixture was stirred at room temperature for 24
hours before being concentrated in vacuo. Purification by column
chromatography, on elution with 35% ethyl acetate in petroleum ether
(60-80.degree. C.), afforded a white solid that was further purified
by reprecipitation from dichloromethane/hexane: 0.340 g, (72%) m.p,
152-153.degree. C.; .sup.1H-NMR (250 MHz, CDCl.sub.3, TMS) 1.57
(s, 9H, C(CH.sub.3).sub.3), 1.93, 2.63 (2.times.m, 2H, indanyl 2-H),
2.97 (m, 2H, indanyl 3-H), 3.55 (s, 3H, OCH.sub.3), 4.06 (s, 2H,
CH.sub.2OMe), 5.04 (t, J=6.50 Hz, 1H, 1-H), 6.64 (d, J=8.78 Hz,
2H, 3,5-H), 7.51, 8.33 (2.times.s, each 1H, indanyl 4-H, 7-H), 7.85
(d, J=8.75 Hz, 2,6-H), 8.93 (s, 1H, CONH); MS (ESI, m/z) 499, 497
{(M+Na).sup.+, bromine isotopic pattern}.
tert-Butyl 4-[N-(5-methoxyacetamido-6-cyanoindan-1-yl)amino]benzoate
To a solution of tert-butyl 4-[N-(5-methoxyacetamido-6-bromoindan-1-yl)amino]benzoate
(0.714 g, 1.50 mol) in NMP (8 ml) [1-methyl-2-pyrrolidone] was added
copper (I) cyanide (0.230 g, 2.55 mmol). The reaction mixture was
placed in an oil-bath preheated to 140.degree. C. and stirred at
this temperature for 2 h. More copper (I) cyanide (0.100 g, 1.10
mmol) was then added and stirring was continued for a longer 3 hours.
The reaction mixture was allowed to cool to room temperature, then
poured into a mixture of aqueous ammonia (d=0.88, 7 ml) and ice
(.about.20 ml) and the resulting brown mixture was stirred at room
temperature for .about.5 min. The brown solid was collected by filtration
washed with plenty of water, then suspended in dichloromethane (100
ml). The mixture was stirred at room temperature for 10 min, dried
(Na.sub.2SO.sub.4), and concentrated in vacuo. Purification by column
chromatography, on elution with 35% ethyl acetate in hexane, afforded
an off white solid that was reprecipitated from dichloromethane-ethyl
acetate/hexane: 0.328 g, (52%) m.p. 163-164.degree. C. .sup.1H-NMR
(250 MHz, DMSO-d.sub.6, TMS) 1.50 (s, 9H, C(CH.sub.3).sub.3), 1.85,
2.58 (2.times.m, 2H, indanyl 2-H), 2.89 (m, 2H, indanyl 3-H), 3.41
(s, 3H, OCH.sub.3), 4.05 (s, 2H, CH.sub.2OMe), 5.06 (m, 1H, indanyl
1-H), 6.73 (d, J=8.82 Hz, 2H, 3,5-H), 6.82 (d, J=8.37 Hz, 1H, N.sup.10--H),
7.59, 7.57 (2.times.s, each 1H, indanyl 4-H, 7-H), 7.66 (d, J=8.77
Hz, 2,6-H), 9.88 (s, 1H, CONH), MS (ESI, m/z) 444 {(M+Na).sup.+,
100%}; Found: C, 68.21; H, 6.47; N, 9.81; C.sub.24H.sub.27N.sub.3O.sub.4
requires C, 68.39; H, 6.46; N, 9.97%.
tert-Butyl 4-{N-[(6RS)-2-methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclope-
nta[g]quinazolin-6-yl]amino}benzoate
A mixture of tert-butyl 4-[N-(5-methoxyacetamido-6-cyanoindan-1-yl)amino]benzoate
(0.295 g, 0.70 mmol), ethanol (3.2 ml), and water (0.64 ml) was
cooled in an ice-bath, then 30% aqueous H.sub.2O.sub.2 solution
(0.60 ml) was added followed by granulated sodium hydroxide pellets
(0.047 g, 1.19 mmol). The reaction mixture was stirred at .about.0.degree.
C. for 10 min, then it was placed in an oil bath preheated to 55.degree.
C. and stirred at this temperature for 30 min. The reaction mixture
was allowed to cool to room temperature, then the solvents were
removed in vacuo and the residue was suspended in water (.about.15
ml). The pH of this mixture was adjusted to .about.12 with 1N NaOH
(got a clear solution), then to .about.4 with 1N hydrochloric acid.
The off white precipitate was collected by filtration, washed with
water, dried in vacuo over P.sub.2O.sub.5: 0.262 g (89%), m.p. >122.degree.
C. (softens); .sup.1H-NMR (250 MHz, DMSO-d.sub.6, TMS) 1.50 (s,
9H, C(CH.sub.3).sub.3), 1.87, 2.56 (2.times.m, each 1H, 7-H), 3.00
(m, 2H, 8-H), 3.34 (s, 3H, OCH.sub.3), 4.30 (s, 2H, 2-CH.sub.2),
5.16 (m, 1H, 6-H), 6.78 (d, J=8.55 Hz, 2H, 3',5'-H), 6.89 (d, J=8.10,
N.sup.10--H), 7.52, 7.90 (2.times.s, each 1H, 5-H, 9-H), 7.67 (d,
J=8.45 Hz, 2',6'-H), 12.12 (s, 1H, N.sup.3--H); MS (ESI, m/z) 444
{(M+Na).sup.+, 40%}; Found: C, 67.19; H, 6.31; N, 9.69; C.sub.24H.sub.27N.sub.3O.sub.4
0.5H.sub.2O requires C, 66.96; H, 6.50; N, 9.76%.
Dicobalthexacarbonyl Propargyl Alcohol Complex
This is a known compound (K.-D. Roth and U. Muller, Tetrahedron
Letters 1993, 34, 2919) and in this study was prepared according
to Nicholas' methodology (K. L. Salazar and K. M. Nicholas, Tetrahedron
2000, 56, 2211): To a round bottom flask charged with Co.sub.2(CO).sub.6
(5.12 g, 15.0 mmol) under argon in a well ventilated hood was added
anhydrous dichloromethane (170 ml) followed by a solution of propargyl
alcohol (0.840 g, 15.0 mmol) in anhydrous dichloromethane (20 ml).
The deep red reaction mixture was stirred at room temperature for
7 h under argon, then it was filtered through a thin layer of neutral
alumina. The filtrate was concentrated in vacuo to give a red residue.
Purification by column chromatography, on elution with 40% diethyl
ether in hexane, afforded the desired product as a red solid 4.10
g (80%); .sup.1H-NMR (250 MHz, CDCl.sub.3, TMS) 1.83 (t, J=6.0 Hz,
1H, OH), 4.80 (d, J=6.0 Hz, 2H, CH.sub.2), 6.08 (s, 1H, C--H).
(Propargyl)Co.sub.2(CO).sub.6.sup.+BF.sub.4.sup.-
This is a known compound (K.-D. Roth and U. Muller, Tetrahedron
Letters 1993, 34, 2919) and in this study was prepared according
to Nicholas' methodology (K. L. Salazar and K. M. Nicholas, Tetrahedron
2000, 56, 2211): To a round bottom flask charged with dicobalthexacarbonyl
propargyl alcohol complex (1.60 g, 4.7 mmol) under argon was added
(syringed via a septum) propionic acid (2.2 ml). The reaction mixture
was cooled to -20.degree. C. and then a solution of HBF.sub.4 in
diethyl ether (54% w/w, 2.05 ml) was slowly syringed into the reaction
mixture via a septum. The reaction mixture was stirred at -20.degree.
C. for 40 min, then cooled diethyl ether (50 ml) was added. Trituration
afforded a red precipitate that was collected by filtration, washed
with plenty of dry diethyl ether and dried in vacuo over P.sub.2O.sub.5:
1.71 g (90%). This was immediately used in the next reaction without
any further purification.
tert-Butyl 4-{N-[(6RS)-2-methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclope-
nta[g]quinazolin-6-yl]-N-(prop-2-ynyl)amino}benzoate
To a round-bottomed flask containing the tetrafluoroborate salt
(propargyl)Co.sub.2(CO).sub.6.sup.+BF.sub.4.sup.- (0.271 g, 0.66
mmol) was added anhydrous dichloromethane (dried by distillation
over P.sub.2O.sub.5; 22 ml). The nearly clear red dark solution
was stirred at room temperature for few minutes under argon, then
tert-butyl 4-{N-[(6RS)-2-methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quin-
azolin-6-yl]amino}benzoate (0.215 g, 0.51 mmol) was added in one
portion. Stirring was continued at this temperature for 5 min then
diisopropylethylamine (0.18 ml, 1.04 mmol) was added and the reaction
mixture was stirred at room temperature for 45 min under argon.
The reaction mixture was partitioned between ethyl acetate (150
ml) and brine (60 ml). The aqueous layer was extracted with more
ethyl acetate (2.times.50 ml). The combined extracts were washed
with 10% aqueous citric acid (50 ml), brine (50 ml), dried (Na.sub.2SO.sub.4),
and concentrated in vacuo. Purification by column chromatography,
on elution with 40% ethyl acetate in dichloromethane, gave a red
solid: 0.285 g (75%). To a solution of this complex (0.267 g, 0.36
mmol) in ethanol (60 ml) was added Fe(NO.sub.3).sub.3.9H.sub.2O
(.about.8.0 g). The clear solution was stirred at room temperature
for 10 min then a second portion of Fc(NO.sub.3).sub.3.9H.sub.2O
(.about.4.0 g) was added. The reaction mixture was stirred at room
temperature for a longer 5 min then a final portion of Fe(NO.sub.3).sub.3.9H.sub.2O
(.about.5.0 g) was added; the nearly clear solution was turned into
a dark red mixture. Stirring was continued at room temperature for
an extra 25 min, then the reaction mixture was partitioned between
ethyl acetate (150 ml) and dilute brine (700 ml). The aqueous layer
was extracted with more ethyl acetate (2.times.70 ml), The combined
organics were washed with brine (3.times.70 ml), dried (Na.sub.2SO.sub.4),
and concentrated in vacuo. Purification by column chromatography,
on elution with 2% methanol in dichloromethane, afforded a white
solid which was reprecipitated from dichloromethane/hexane: 0.122
g (74%), m.p. 191-192.degree. C.; .sup.1H-NMR (250 MHz, DMSO-d.sub.6,
TMS) 1.51 (s, 9H, C(CH.sub.3).sub.3), 2.23, 2.53 (m-obscured by
DMSO peak) (2.times.m, each 1H, 7-H), 2.95-3.20 (m, 3H, C.ident.CH,
8-H), 3.34 (s (obscured by the H.sub.2O peak), 3H, OCH.sub.3), 3.96
(ABq, J=18.0 Hz, 2H, CH.sub.2C.ident.C), 4.31 (s, 2H, 2-CH.sub.2),
5.79 (t, J=7.0 Hz, 1H, 6-H), 7.02 (d, J=9.01 Hz, 2H, 3',5'-H), 7.58,
7.80 (2.times.s, each 1H, 5-H, 9-H), 7.76 (d, J=8.45 Hz, 2',6'-H),
12.17 (s, 1H, N.sup.3--H); MS (ESI, m/z) 482 {(M+Na).sup.+, 10%};
Found: C, 70.32; H, 6.31; N, 9.09; C.sub.27H.sub.29N.sub.3O.sub.4
requires C, 70.57; H, 6.36; N, 9.14%.
4-{N-[(6RS)-2-Methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quina-
zolin-6-yl]-N-(prop-2-ynyl)amino}benzoic acid
A solution of tert-butyl 4-{N-[(6RS)-2-methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quin-
azolin-6-yl]-N-(prop-2-ynyl)amino}benzoate (0.069 g, 0.15 mmol)
in dichloromethane (1 ml) and trifluoroacetic acid (3 ml) was stirred
at room temperature for 1 hour and 10 min, then the solvents were
removed in vacuo. The residue was triturated with diethyl ether
and the precipitate was collected by filtration, washed with diethyl
ether and dried in vacuo over P.sub.2O.sub.5 to afford the title
compound as the trifluoroacetate salt: 0.061 g, m.p. 225.degree.
C. (dec); .sup.1H-NMR (250 MHz, DMSO-d.sub.6, TMS) 2.23, 2.53 (obscured
by DMSO peak) (2.times.m, each 1H, 7-H), 2.90-3.20 (m, 3H, C.ident.CH,
8-H), 3.34 (s (obscured by the H.sub.2O peak), 3H, OCH.sub.3), 3.97
(ABq, J=18.0 Hz, 2H, CH.sub.2C.ident.C), 4.32 (s, 2H, 2-CH.sub.2),
5.79 (t, J=8.1 Hz, 1H, 6-H), 7.03 (d, J=9.02 Hz, 2H, 3',5'-H), 7.58,
(s, 1H, 9-H), 7.81 (m, 3H, 5-H, 2',6'-H), 12.17 (s, 1H, N.sup.3--H);
MS (ESI, m/z) 426 {(M+Na).sup.+, 25%}, 404 {(M+H).sup.+, 70%}.
Tri-tert-butyl N-{N-{4-[N-((6RS)-2-methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[-
g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-D-glu-
tamate
To a mixture of 4-{N-[(6RS)-2-methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quin-
azolin-6-yl]-N-(prop-2-ynyl)amino}benzoic acid trifluoroacetate
salt (0.056 g, .about.0.14 mmol), tri-tert-butyl L-.gamma.-glutamyl-D-glutamate
(0.090 g, 0.20 mmol) and anhydrous DMF (2.5 ml) was added diethyl
cyanophosphonate (0.050 g, 0.31 mmol) followed by triethylamine
(0.035 g, 0.35 mmol). The clear solution was stirred at room temperature
for 2 hours, then it was partitioned between ethyl acetate (150
ml) and water (80 ml). The aqueous layer was extracted with ethyl
acetate (2.times.70 ml). The combined organics were washed with
10% aqueous citric acid (2.times.40 ml), saturated sodium bicarbonate
solution (100 ml) and brine (100 ml), dried (Na.sub.2SO.sub.4),
and concentrated in vacuo. Purification by column chromatography,
on elution with 1.5% methanol in ethyl acetate, afforded a white
solid that was further purified by trituration with hexane with
the aid of some dichloromethane: 0.072 g (64%); m.p. >120.degree.
C.; .sup.1H-NMR (250 MHz, DMSO-d.sub.6, TMS) 1.38, 1.39, 1.41 (3.times.s,
27H, 3.times.C(CH.sub.3).sub.3), 1.60-2.35 (m, 9H, 2.times..beta.-CH.sub.2,
2.times..gamma.-CH.sub.2, 7-H), 2.52 (m obscured by DMSO peak, 1H,
7-H), 2.90-3.25 (m, 3H, C.ident.CH, 8-H), 3.97 (ABq, J=17.0 Hz,
2H, CH.sub.2C.ident.C), 4.08, 4.12 (2.times.m, 2H, 2.times..alpha.-CH),
4.32 (s, 2H, 2-CH.sub.2), 5.77 (t, J=7.50 Hz, 1H, 6-H), 7.02 (d,
J=8.85 Hz, 2H, 3',5-H), 7.58 (s, 1H, 9-H), 7.80 (d, J=9.0 z, 2H,
2',6'-H), 7.82 (s, 1H, 5-H), 8.17 (d, J=8.12 Hz, 1H, CONH), 8.36
(d, J=7.00 Hz, 1H, CONH), 12.16 (s, 1H, N.sup.3--H); MS (ESI, m/z)
852 {(M+Na).sup.+, 20%}, 830 {(M+H).sup.+, 100%}, Found C, 64.71;
H, 7.21; N, 8.27. C.sub.45H.sub.59N.sub.5O.sub.10 requires C, 65.12;
H, 7.17; N, 8.44%.
N-{N-{4-[N-(6RS)-2-Methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]-
quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-D-gluta-
mic acid
A solution of tri-tert-butyl N-{N-{4-[N-((6RS)-2-methoxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[-
g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]-benzoyl}-L-.gamma.-glutamyl}-D-gl-
utamate (0.056 g, 0.07 mmol) in trifluoroacetic acid (4.5 ml) was
stirred at room temperature for 1 hour and 10 min with protection
from the light. The solvent was then removed in vacuo and the residue
was suspended in water (4 ml). The pH was adjusted to .about.10
with 1N NaOH, then to .about.4 with 1N hydrochloric acid. The white
precipitate was collected by filtration and dried in vacuo over
P.sub.2O.sub.5: 0.020 g (45%), m.p. 150-155.degree. C. (softens),
.sup.1H-NMR (250 MHz, DMSO-d.sub.6, TMS) 1.60-2.30 (m, 9H, 2.times..beta.-CH.sub.2,
2.times..gamma.-CH.sub.2, 7-H), 2.52 (m obscured by DMSO peak, 1H,
7-H), 2.90-3.25 (m, 3H, C.ident.CH, 8-H), 3.36 (s, 3H, OCH.sub.3),
3.97 (ABq, J=17.0 Hz, 2H, CH.sub.2C.ident.C), 4.20, 4.34 (2.times.m,
2H, 2.times..alpha.-CH), 4.32 (s, 2H, 2-CH.sub.2), 5.77 (t, J=8.02
Hz, 1H, 6-H), 7.02 (d, J=8.85 Hz, 2H, 3',5-H), 7.58 (s, 1H, 9-H),
7.81 (d, J=9.0 z, 2H, 2',6'-H), 7.83 (s, 1H, 5-H), 8.14 (d, J=8.12
Hz, 1H, CONH), 8.33 (d, J=7.78 Hz, 1H, CONH), 12.10 (s, 1H, N.sup.3--H);
MS (ESI, m/z) 662 {(M+H).sup.+, 100%}.
EXAMPLE 2
Synthesis of CB300945 (2-CH.sub.2OH Derivative of CB300638)
##STR00007##
2-Hydroxymethyl-3,4,7,8-tetrahydro-6H-cyclopenta[g]quinazolin-4-one
A solution of caesiun acetate (14.4 g, 75.2 mmol) in dry DMF (40
ml) was heated to 60.degree. C. under argon for 30 min. The mixture
was cooled to 40.degree. C. and a suspension of 2-chloromethyl-3,4,7,8-tetrahydro-6H-cyclopenta[g]quinazolin-4-one
(L. Skelton, V. Bavetsias, A. Jackman, WO 00/050417-A1; 2.2 g, 9.4
mmol) in dry DMF (60 ml) was added via a cannula. The mixture was
heated to 80.degree. C. under argon for 16 h. The mixture was cooled
to room temperature and the solvent was removed in vacuo. The residue
was suspended in water (50 ml) and MeOH (20 ml). The pH was adjusted
to 12.5 with 1M sodium hydroxide solution and the brown suspension
was stirred for 2 h at room temperature. The insoluble brown solid
was removed by filtration and the resulting solution was acidified
to pH 5 with 1M hydrochloric acid. The precipitate was collected
by filtration, washed with acidified water and dried in vacuo over
P.sub.2O.sub.5 to yield the product as a pale yellow solid (1.17
g, 58%); m.p. 205-210.degree. C.; .sup.1H NMR (DMSO-d.sub.6) .delta.
2.07 (quin, J=7.4 Hz, 2H, 7-H), 2.98 (q, J=6.95 Hz, 4H, 6-H and
8-H), 4.38 (s, 2H, 2-CH.sub.2), 7.46 (s, 1H, 9-H), 7.92 (s, 1H,
5-H); MS (FAB-m/z): Found 217 [(M+H).sup.+, 100%]; HRMS: measured
217.0977; calculated for C.sub.12H.sub.13N.sub.2O.sub.2 (M+H).sup.+:
217.0977; Found C, 64.01; H, 5.23; N, 12.34. C.sub.12H.sub.13N.sub.2O.sub.2.1/2H.sub.2O
requires C, 63.93; H, 5.77; N, 12.43%.
2-2,2-Dimethylpropionyloxymethyl)-3,4,7,8-tetrahydro-6H-cyclopenta[g]quina-
zolin-4-one
2-Hydroxymethyl-3,4,7,8-tetrahydro-6H-cyclopenta[g]quinazolin-4-one
(1.0 g, 4.6 mmol), triethylamine (0.77 ml, 5.6 mmol), DMAP (50 mg,
0.4 mmol) and anhydrous CH.sub.2Cl.sub.2 (50 ml) were mixed in a
flask under argon. Pivalic anhydride (1.2 ml, 6.0 mmol) was added
dropwise and the suspension stirred at room temperature under argon
for 5 h. The solvent was removed in vacuo and the residue partitioned
between EtOAc (100 ml) and saturated aqueous NaHCO.sub.3 (100 ml).
The organic extract was washed with saturated aqueous NaHCO.sub.3
(70 ml), water (70 ml), brine (70 ml), dried (Na.sub.2SO.sub.4)
and the solvent removed in vacuo. The residue was triturated with
hexane (60 ml) and the product collected by filtration as a yellow
solid (1.21 g, 87%); m.p. 185-190.degree. C.; .sup.1H-NMR (DMSO-d.sub.6)
.delta. 1.22 (s, 9H, CMe.sub.3), 2.07 (quin, J=7.4 Hz, 2H, 7-H),
2.98 (q, J=5.72 Hz, 4H, 6-H and 8-H), 4.94 (s, 2H, 2-CH.sub.2),
7.42 (s, 1H, 9-H), 7.92 (s, 1H, 5-H), 12.20 (br, 1H, NH); MS (FAB,
m/z): Found 301 [(M+H).sup.+, 100%]; HRMS: measured 301.1539; calculated
for C.sub.17H.sub.21N.sub.2O.sub.3 (M+H).sup.+: 301.1552; Found
C, 67.65; H, 6.54; N, 9.54. C.sub.17H.sub.20N.sub.2O.sub.3 requires
C, 67.98; H, 6.71; N, 9.33%.
2-(2,2-Dimethylpropionyloxymethyl)-3,4,7,8-tetrahydro-6H-cyclopenta-[g]qui-
nazolin-4,6-dione and 2-(2,2-Dimethylpropionyloxymethyl)-3,4,7,8-tetrahydro-6H-cyclopenta[g]qui-
nazolin-4,8-dione
To a stirred solution of (Ph.sub.3SiO).sub.2CrO.sub.2 (L. M. Baker
and W. L. Carrick, J. Org. Chem. 1970, 35, 774) (10.6 mg, 0.017
mmol) in CH.sub.2Cl.sub.2 (5 ml) was added sequentially aqueous
70% tert-butyl hydroperoxide (0.18 ml, 1.3 mmol) and 2-(2,2-dimethylpropionyloxymethyl)-3,4,7,8-tetrahydro-6H-cyclopenta[g]qui-
nazolin-4-one (0.1 g, 0.33 mmol). The mixture was stirred at room
temperature with protection from the light for 24 h. The solvents
were removed in vacuo and the residue purified by column chromatography
(20 g of silica gel) eluting with a gradient of 10-30% EtOAc in
CHCl.sub.3 to yield 2-(2,2-dimethylpropionyloxymethyl)-3,4,7,8-tetrahydro-6H-cyclopenta-
[g]quinazolin-4,6-dione as a white solid (47 mg, 45%); m.p. 185-190.degree.
C.; .sup.1H-NMR (DMSO-d.sub.6) .delta. 1.23 (s, 9H, CMe.sub.3),
2.72 (m, 2H, 7-H), 3.25 (m, 2H, 8-H), 5.00 (s, 2H, 2-CH.sub.2),
7.70 (s, 1H, 9-H), 8.29 (s, 1H, 5-H), 12.20 (br, 1H, NH); MS (FAB,
m/z): Found 315 [(M+H).sup.+, 100%], 337 [(M+Na).sup.+, 75%]; HRMS:
measured 315.1360; calculated for C.sub.17H.sub.19N.sub.2O.sub.4
(M+H).sup.+: 315.1345; Found C, 64.188; H, 5.72; N, 8.81. C.sub.11H.sub.18N.sub.2O.sub.4.0.2H.sub.2O
requires C, 64.23; H, 5.79; N, 8.82%.
2-2,2-Dimethylpropionyloxymethyl)-3,4,7,8-tetrahydro-6H-cyclopenta[g]-quin-
azolin-4,8-dione, .sup.1H-NMR (DMSO-d.sub.6) .delta. 1.23 (s, 9H,
CMe.sub.3), 2.76 (m, 2H, 7-H), 3.26 (m, 2H, 8-H), 4.98 (s, 2H, 2-CH.sub.2),
7.72 (s, 1H, 9-H), 8.29 (s, 1H, 5-H), 12.3 (br, 1H, NH).
tert-Butyl 4-[N-((6RS)-2-(2,2-dimethylpropionyloxymethyl)-4-oxo-3,4,7,8-te-
trahydro-6H-cyclopenta[g]quinazolin-6-yl)amino]benzoate
A suspension of 2-(2,2-dimethylpropionyloxymethyl)-3,4,7,8-tetrahydro-6H-cyclopenta[g]qui-
nazolin-4,6-dione (0.47 g, 1.50 mmol) in anhydrous methanol (33
ml) and anhydrous CH.sub.2Cl.sub.2 (5 ml) was treated with tert-butyl
4-aminobenzoate (0.34 g, 1.78 mmol) followed by decaborane (0.07
g, 0.58 mmol) and the mixture stirred at room temperature under
argon for 18 h. The solvent was removed in vacuo and the residue
purified by column chromatography (50 g of silica gel) eluting with
30% ethyl acetate in CH.sub.2Cl.sub.2 to yield the desired product
as a white solid (0.43 g, 58%); m.p. 231.degree. C.; .sup.1H-NMR
(CDCl.sub.3) .delta. 1.26 (s, 9H, CMe.sub.3), 1.58 (s, 9H, CO.sub.2CMe.sub.3),
2.00 (m, 1H, 7-H), 2.72 (m, 1H, 7-H), 3.08 (m, 2H, 8-H), 5.10 (s,
2H, 2-CH.sub.2), 5.15 (m, 1H, 6-H), 6.67 (d, J=8.8 Hz, 2H, 3'-H,
5'-H), 7.58 (s, 1H, 9-H), 7.87 (d, J=8.8 Hz, 2H, 2'-H, 6'-H), 8.24
(s, 1H, 5-H); MS (FAB, m/z): Found 491 [(M+H).sup.+, 25%], 514 [(M+Na).sup.+,
100%]; Found C, 68.37; H, 6.86; N, 8.35. C.sub.28H.sub.33N.sub.3O.sub.5
requires C, 68.41; H, 6.77; N, 8.55%.
tert-Butyl 4-[N-((6RS)-2-(2,2-dimethylpropionyloxymethyl)-4-oxo-3,4,7,8-te-
trahydro-6H-cyclopenta[g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoate
A suspension of (propargyl)Co.sub.2(CO).sub.6.sup.+BF.sub.4.sup.-
(213 mg, 0.52 mmol) in anhydous CH.sub.2Cl.sub.2 (25 ml) was treated
with tert-butyl 4[-N-((6RS)-2-(2,2-dimethyl-propionyloxymethyl)-4-oxo-3,4,7,8-tetrahydro--
6H-cyclopenta[g]quinazolin-6-yl)amino]benzoate (200 mg, 0.41 mmol)
and the red solution stirred at room temperature under argon for
15 minutes. Diisopropylethylamine (0.15 ml, 0.86 mmol) was added
and the mixture stirred at room temperature under argon for 1 h.
The mixture was partitioned between ethyl acetate (30 ml) and brine
(30 ml). The organic extract was dried (Na.sub.2SO.sub.4) and the
solvent removed in vacuo. The residue was purified by column chromatography
(20 g of silica gel) eluting with a gradient of 0-10% ethyl acetate
in CH.sub.2Cl.sub.2 to yield the complex as a red oil (191 mg, 58%),
.sup.1H-NMR (CDCl.sub.3) .delta. 1.26 (s, 9H, CMe.sub.3), 1.59 (s,
9H, CO.sub.2CMe.sub.3), 2.31 (m, 1H, 7-H), 2.62 (m, 1H, 7-H), 3.13
(m, 2H, 8-H), 4.57 (AB system, J=16.9 Hz, 2H, propargyl CH.sub.2),
5.09 (s, 2H, 2-CH.sub.2), 5.63 (t, J=8.3, 1H, 6-H), 5.98 (s, 1H,
propargyl CH), 6.91 (d, J=8.9 Hz, 2H, 3'-H, 5'-H), 7.61 (s, 1H,
9-H), 7.90 (d, J=8.9 Hz, 2H, 2'-H, 6'-H), 8.14 (s, 1H, 5-H), 10.25
(br s, 1H).
A solution of this complex (186 mg, 0.23 mmol) in ethanol (30 ml)
was treated with Fe(NO.sub.3).sub.3.9H.sub.2O (1.1 g) and the solution
stirred at room temperature for 2 h. The solution was partitioned
between ethyl acetate (30 ml) and water (30 ml). The organic extract
was washed with brine (30 ml), dried (Na.sub.2SO.sub.4) and the
solvent removed in vacuo. The residue was purified by column chromatography
(20 g of silica gel) eluting with 10% ethyl acetate in CH.sub.2Cl.sub.2
to yield the desired product as a white solid (94 mg, 78%); m.p.
134.degree. C.; .sup.1H-NMR (CDCl.sub.3) .delta. 1.32 (s, 9H, CMe.sub.3),
1.61 (s, 9H, CO.sub.2CMe.sub.3), 2.23 (s, 1H, propargyl CH), 2.38
(m, 1H, 7-H), 2.62 (m, 1H, 7-H), 3.07 (m, 1H, 8-H), 3.25 (m, 1H,
8-H), 3.94 (AB system, J=18.6 Hz, 2H, propargyl CH.sub.2), 5.12
(s, 2H, 2-CH.sub.2), 5.68 (t, J=8.2 Hz, 1H, 6-H), 6.99 (d, J=9.1
Hz, 2H, 3'-H, 5'-H), 7.63 (s, 1H, 9-H), 7.95 (d, J=9.0 Hz, 2H, 2'-H,
6'-H), 8.16 (s, 1H, 5-H), 9.55 (br s, 1H); MS (ESI, m/z) 552 {(M+Na).sup.+,
100%}, 530 {(M+H).sup.+, 20%}; Found C, 70.14; H, 6.80; N, 7.73.
C.sub.31H.sub.35N.sub.3O.sub.5 requires C, 70.30; H, 6.66; N, 7.93%.
4-[N-((6RS)-2-(2,2-Dimethylpropionyloxymethyl)-4-oxo-3,4,7,8-tetrahydro-6H-
-cyclopenta[g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoic acid
A solution of tert-butyl 4-[N-((6RS)-2-(2,2-dimethylpropionyloxymethyl)-4-oxo-3,4,7,8-tetrahydro-6-
H-cyclopenta[g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]-benzoate (80
mg, 0.15 mmol) in trifluoroacetic acid (5 ml) was stirred at room
temperature with protection from the light for 1.5 h. The solvent
was removed in vacuo and the residue triturated with 1:1 diethyl
ether and hexane to yield the desired product as a white solid (81
mg, TFA salt); m.p. 133.degree. C., .sup.1H-NMR (DMSO-d6) .delta.
1.23 (s, 9H, CO.sub.2CMe.sub.3), 2.22 (m, 1H, 7-H), 2.50 (m, 1H,
7-H), 3.03 (m, 2H, 8-H), 3.14 (s, 1H, propargyl CH), 3.97 (AB system,
J=18.8 Hz, 2H, propargyl CH.sub.2), 4.95 (s, 2H, 2-CH.sub.2), 5.79
(t, J=8.6 Hz, 1H, 6-H), 7.03 (d, J=9.0 Hz, 2H, 3'-H, 5'-H), 7.51
(s, 1H, 9-H), 7.81 (d, J=6.6 Hz, 2H, 2'-H, 6'-H), 7.83 (s, 1H, 5-H).
Tri-tert-butyl N-{N-{4-[N-((6RS)-2-(2,2-dimethylpropionyloxymethyl)-4-oxo-3,4,7,8-tetrah-
ydro-6H-cyclopenta[g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gam-
ma.-glutamyl}-D-glutamate
A solution of 4-[N-((6RS)-2-(2,2-dimethylpropionyloxymethyl)-4-oxo-3,4,7,8-tetrahydro-6-
H-cyclopenta[g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoic acid
(80 mg, 0.15 mmol) in anhydrous dimethylformamide (7 ml) was treated
with tri-tert butyl-L-.gamma.-glutamyl-D-glutamate (150 mg, 0.33
mmol), diethyl cyanophosphonate (0.06 ml, 0.40 mmol) and triethylamine
(0.06 ml, 0.40 mmol). The solution was stirred at room temperature
under argon with protection from the light for 2.5 h. The solution
was partitioned between ethyl acetate (25 ml) and water (25 ml).
The aqueous layer was extracted with ethyl acetate (2.times.20 ml).
The combined organic extracts were washed with 10% aqueous citric
acid (2.times.30 ml), saturated aqueous NaHCO.sub.3 (30 ml), dilute
brine (30 ml), dried (Na.sub.2SO.sub.4) and the solvent removed
in vacuo. The residue was purified by column chromatography (30
g of silica gel) eluting with 40% ethyl acetate in CH.sub.2Cl.sub.2
to yield the desired product as a white solid (94 mg, 62%); m.p.
109.degree. C.; .sup.1H-NMR (CDCl.sub.3) .delta. 1.29 (s, 9H, --COCMe.sub.3),
1.43 (s, 9H, COOCMe.sub.3), 1.47 (s, 9H, COOCMe.sub.3), 1.48 (s,
9H, COOCMe.sub.3), 1.60-2.10 (m, 5H, 2.times.glu .beta.-CH.sub.2,
7-CH), 2.21 (s, 1H, propargyl CH), 2.22-2.50 (m, 4H, 2.times.glu
.gamma.-CH.sub.2), 2.59 (m, 1H, 7-H), 3.08 (m, 1H, 8-H), 3.20 (m,
1H, 8-H), 3.92 (AB system, J=19.0 Hz, 2H, propargyl CH.sub.2), 4.48,
4.76 (2.times.m, 2H, 2.times.glu .alpha.-CH), 5.12 (s, 2H, 2-CH.sub.2),
5.64 (t, J=8.1 Hz, 1H, 6-H), 6.99 (d, J=8.8 Hz, 2H, 3'-H, 5'-H),
7.07 (m, 2H, 2.times.CONH), 7.64 (s, 1H, 9-H), 7.80 (d, J=8.8 Hz,
2H, 2'-H, 6'-H), 8.13 (s, 1H, 5-H); MS (ESI, m/z) 922 {(M+Na).sup.+,
100%}, 900 {(M+H).sup.+, 40%}, Found C, 64.85; H, 7.23; N, 7.33.
C.sub.49H.sub.65N.sub.5O.sub.11.0.5H.sub.2O requires C, 64.76; H,
7.27; N, 7.71%.
N-{N-{4-[N-((6RS)-2-Hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g-
]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-D-glut-
amic acid
Tri-tert-butyl N-{N-{4-[N-((6RS)-2-(2,2-dimethylpropionyloxymethyl)-4-oxo-3,4,7,8-tetrah-
ydro-6H-cyclopenta[g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]-benzoyl}-L-.ga-
mma.-glutamyl}-D-glutamate (80 mg, 0.09 mmol) was dissolved in trifluoroacetic
acid (5 ml) and stirred at room temperature with protection from
the light for 1 h. The solvent was removed in vacuo and the residue
dissolved in methanol (3 ml) and water (3 ml). The pH of the solution
was adjusted to pH 12 with 1M sodium hydroxide solution and stirred
at room temperature for 6 h. The solution was acidified to pH 4
with 1M hydrochloric acid and cooled to 0.degree. C. The precipitate
was collected by filtration and dried under vacuum over P.sub.2O.sub.5
to yield the desired product as a pale brown solid (27 mg, 47%);
m.p. 172.degree. C.; .sup.1H-NMR (DMSO-d.sub.6) .delta. 1.60-2.10
(m, 5H, 2.times.glu .beta.-CH.sub.2, 7-CH), 2.15-2.40 (m, 5H, 2.times.glu
.gamma.-CH.sub.2, 7-H), 2.99 (m, 1H, 8-H), 3.12 (s, 1H, propargyl
CH), 3.16 (m, 1H, 8-H), 3.98 (AB system, J=19.9 Hz, 2H, propargyl
CH.sub.2), 4.18, 4.30 (2.times.m, 2H, 2.times.glu .alpha.-CH), 4.36
(s, 2H, 2-CH.sub.2), 5.58 (br s, 1H, --OH), 5.77 (t, J=7.9 Hz, 1H,
6-H), 7.01 (d, J=8.9 Hz, 2H, 3'-H, 5'-H), 7.54 (s, 1H, 9-H), 7.80
(d, J=8.5 Hz, 2H, 2'-H, 6'-H), 7.82 (s, 1H, 5-H), 8.15 (d, J=7.5
Hz, 1H), 8.35 (d, J=7.2 Hz, 1H) (2.times.CONH); MS (ESI, m/z) 670
{(M+Na).sup.+, 45%}, 648 {(M+H).sup.+, 100%}; HRMS: measured 648.2313;
calculated for C.sub.32H.sub.35N.sub.5O.sub.10 (M+H).sup.+: 648.2306.
EXAMPLE 3
Synthesis of CB300960 (N-methyl Derivative of CB300945)
##STR00008##
4-{N-[(6RS)-2-Hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quina-
zolin-6-yl]-N-(prop-2-ynyl)amino}benzoic acid
Method A: A solution of tert-butyl 4-{N-[(6RS)-2-(2,2-dimethylpropionyloxymethyl)-4-oxo-3,4,7,8-tetrahydro-6-
H-cyclopenta[g]quinazolin-6-yl]-N-(prop-2-ynyl)amino}benzoate (0.150
g, 0.28 mmol) in dichloromethane (2 ml) and trifluoroacetic acid
(6 ml) was stirred at room temperature for 1 hour. The solvents
were then removed in vacuo, and the residue was suspended in methanol
(3 ml) and water (5 ml). The pH was adjusted to .about.10 with 1N
NaOH (1.1 ml), and the mixture was stirred at room temperature for
4 hours. The reaction mixture was diluted with water (5 ml) and
the pH was adjusted to .about.5 with 1N HCl. The solid was then
collected by filtration, but .sup.1H-NMR indicated no complete removal
of the pivaloyl group. This solid was suspended into the filtrate
and then 1N NaOH (0.9 ml, 0.9 mmol) was added (pH .about.12). The
mixture was stirred at room temperature for 3.5 hours, then more
1N NaOH (0.2 ml) was added, and the mixture was stirred at room
temperature for a further 0.5 hours. The pH was then adjusted to
.about.5.0 with 1N HCl. The off-white precipitate was collected
by filtration, washed with water, and dried in vacuo over P.sub.2O.sub.5:
0.086 g, (79%); .sup.1H-NMR (250 MHz, DMSO-d.sub.6, TMS) 2.22 (m,
1H 7-CH), 2.90-3.30 (m, 3H, C.ident.CH, 8-H), 3.97 (ABq, J=18.6
Hz, 2H, CH.sub.2C.ident.C), 4.37 (d, J=6.1 Hz, 2H, 2-CH.sub.2),
5.56 (t, 1H, CH.sub.2OH), 5.78 (t, J=7.51 Hz, 1H, 6-H), 7.03 (d,
J=8.9 Hz, 2H, 3',5'-H), 7.55 (s, 1H, 9-H), 7.82 (m, 3H, 2',6'-H,
5-H), MS (ESI, m/z) 779 {(2M+H).sup.+, 100%}, 390 {(M+H).sup.+,
60%}.
Method B: A solution of tert-butyl 4-{N-[(6RS)-2-hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quin-
azolin-6-yl]-N-(prop-2-ynyl)amino}-benzoate (0.050 g, 0.11 mmol)
in dichloromethane (1 ml) and trifluoroacetic acid (2.4 ml) was
stirred at room temperature for 1 hour. The solvents were then removed
in vacuo, and the residue was triturated with diethyl ether. The
off-white precipitate was collected by filtration, and washed with
ether to obtain the desired product as the trifluoroacetate salt:
0.044 g.
Tri-tert-butyl N-{N-{4-[N-((6RS)-2-hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[-
g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-N-met-
hyl-L-glutamate
To a mixture of 4-{N-[(6RS)-2-hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quin-
azolin-6-yl]-N-(prop-2-ynyl)amino}benzoic acid (0.075 g, .about.0.19
mmol), tri-tert-butyl L-.gamma.-glutamyl-N-methyl-L-glutamate (V.
Bavetsias et al., J. Med. Chem., 1997, 40, 1495-1510, 0.110 g, 0.24
mmol), and anhydrous DMF (2.0 ml) was added diethyl cyanophosphonate
(0.036 g, 0.22 mmol) with the aid of anhydrous DMF (0.2 ml) followed
by triethylamine (0.022 g, 0.22 mmol). The clear solution was stirred
at room temperature for 1.5 hours, then it was partitioned between
ethyl acetate (50 ml) and brine (40 ml). The aqueous layer was extracted
with more ethyl acetate (2.times.50 ml). The combined organics were
washed with 10% aqueous citric acid (40 ml), saturated sodium bicarbonate
solution (40 ml), and brine (40 ml), dried (Na.sub.2SO.sub.4), and
concentrated in vacuo. Purification by column chromatography, on
elution with a gradient of methanol in dichloromethane (0 to 6%),
afforded an off-white solid that was further purified by trituration
with hexane/dichloromethane/diethyl ether: 0.062 g (40%); mp 116-120.degree.
C. (softens); .sup.1H-NMR (250 MHz, DMSO-d.sub.6, TMS) 1.36, 1.37,
1.38, 1.41 (4.times.s, 27H, 3.times.C(CH.sub.3).sub.3), 1.70-2.35
(m) and 2.50 (m obscured by DMSO peak) (10H, 2.times..beta.-CH.sub.2,
2-.gamma..times.CH.sub.2, 7-CH.sub.2), 2.63, 2.82 (2.times.s, 3H,
CONMe), 2.90-3.25 (m, 3H, C.ident.CH, 8-H), 3.97 (ABq, J=17.6 Hz,
2H, CH.sub.2C.ident.C), 4.32 (m, 1H, glu .alpha.-CH), 4.38 (d, J=6.1
Hz, 2H, 2-CH.sub.2), 4.50, 4.82 (2.times.dd, 1H, Meglu .alpha.-CH),
5.56 (t, J=6.9 Hz, 1H, CH.sub.2OH), 5.78 (t, J=7.10 Hz, 1H, 6-H),
7.02 (d, J=8.6 Hz, 2H, 3',5'-H), 7.55 (s, 1H, 9-H), 7.78 (d, J=8.9
Hz, 2H, 2',6'-H), 7.82 (s, 1H, 5-H), 8.32 (m, 1H, CONH), 11.81 (s,
1H, N.sup.3--H); MS (EST, m/z) 830{(M+H).sup.+, 100%}.
N-{N-{4-[N-((6RS)-2-hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g-
]quinazolin-6-yl)-N-(prop-2-ytyl)amino]benzyl}-L-.gamma.-glutamyl}-N-methy-
l-L-glutamic acid
A solution of tri-tert-butyl N-{N-{4-[N-((6RS)-2-hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[-
g]quinazolin-6-yl)-N-(prop-2-ynyl)amino]benzoyl}-L-.gamma.-glutamyl}-N-met-
hyl-L-glutamate (0.060 g, 0.07 mmol) in trifluoroacetic acid (3.5
ml) was stirred at room temperature for 1 hour and 10 min with protection
from the light. The solvent was then removed in vacuo and the residue
was suspended in water (6 ml). The pH was adjusted to .about.10
with 1N NaOH, then to .about.4 with 1N hydrochloric acid. The white
precipitate was collected by filtration, and dried in vacuo over
P.sub.2O.sub.5: 0.035 g (77%), mp >165.degree. C. (dec); .sup.1H-NMR
(250 MHz, DMSO-d.sub.6, TMS) 1.80-2.35 (m) and 2.50 (m obscured
by DMSO peak) (10H, 2.times..beta.-CH.sub.2, 2.times..gamma.-CH.sub.2,
7-CH.sub.2), 2.66, 2.83 (2.times.s, 3H, CONMe), 2.90-3.25 (m, 3H,
C.ident.CH, 8-H), 3.97 (ABq, J=18.4 Hz, 2H, CH.sub.2C.ident.C),
4.32 (m obscured, 1H, glu .alpha.-CH), 4.38 (d, J=5.6 Hz, 2H, 2-CH.sub.2),
4.55, 4.91 (2.times.dd, J=10.0, 4.5 Hz, 1H, Meglu .alpha.-CH), 5.56
(poorly resolved t, 1H, CH.sub.2OH), 5.77 (t, J=8.06 Hz, 1H, 6-H),
7.02 (d, J=7.8 Hz, 2H, 3',5-H), 7.55 (s, 1H, 9-H), 7.81 (d, J=10.1
Hz, 3H, 2',6'-H, 5-H), 8.32 (m, 1H, CONH), 11.82 (s, 1H, N.sup.3--H);
MS (ESI, m/z) 662 {(M+H).sup.+, 100%}; Found: C, 57.52; H, 5.52,
N, 10.17; C.sub.33H.sub.35N.sub.5O.sub.10 1.5 H.sub.2O requires:
C, 57.55; H, 5.56; N, 10.17%.
EXAMPLE 4
In vitro Evaluation
CB300945, the (RS)-C2-CH.sub.2OH analogue of the known cyclopenta[g]-quinazoline,
CB300638 was synthesised as in Example 1. In addition, the C2-NH.sub.2
was made as a comparative example. The activity of this new series
of cyclopenta[g]quinazolines with C2-CH.sub.3 (RS-CB300638), C2-CH.sub.2OH
(RS-CB300945) and C2-NH.sub.2 (RS-CB300944) substitutions were compared
with three other series of quinazoline derivatives in mouse L1210-FBP
cells and human tumour cell lines co-expressing the RFC and .alpha.-FR.
The human A431-FBP cell line was transfected with the .alpha.-FR
and sensitivity compared with the A431 cell line. Human nasopharengeal
KB cells constitutively overexpress this receptor (see Bagnoli et
al. Oncogene, 19, 4754-4763, 2000).
In the quinazoline series, the C2-CH.sub.2OH analogues were found
to have lower affinities for the .alpha.-FR of L1210-FBP cells (0.21
to 0.29) than the 2-CH.sub.3 (0.37 to 0.54) and particularly the
2-NH.sub.2 (1.3 to 1.7) counterparts. In the cyclopenta[g]quinazoline
series the C2-CH.sub.3 analogue (CB300639) had a relative binding
affinity of 0.57. However, unexpectedly the C2-CH.sub.2OH analogue
(CB300945) had a higher affinity than predicted (0.71) and the C2-NH.sub.2
analogue (CB300944) had one lower than predicted (0.57). Thus in
the cyclopenta[g]quinazoline series C2-substitution did not markedly
affect binding to the .alpha.-FR. A similar pattern of binding was
noted for .alpha.-FR expressed by A431-FBP cells (data not shown).
A431-FBP and KB cells were highly sensitive to the C2-CH.sub.3
cyclopenta[g]quinazoline with a L-glu-.gamma.-D-glu ligand (S or
RS-CB300638). However, very little activity of the C2-NH.sub.2 analogue
(PS-CB300944) could be attributed to .alpha.-FR mediated uptake
into either of these cell lines (Tables 13). On the other hand the
C2-CH.sub.2OH analogue (RS-CB300945) was highly potent in A431-FBP
and KB cells and more highly selective for these cells compared
with A431 cells, than RS-CB300638.
Tables 4 and 5 show the structures of the compounds tested.
EXAMPLE 5
Formulation
The following illustrate representative pharmaceutical dosage forms
containing a cyclopenta[g]quinazoline of formula (I), particularly
in pharmaceutically acceptable salt form, for therapeutic or prophylactic
use in humans:
TABLE-US-00002 (a) Tablet I mg/tablet Cyclopenta[g]quinazoline
salt 100 Lactose Ph.Eur. 182.75 Croscarmellose sodium 12.0 Maize
starch paste (5% w/v paste) 2.25 Magnesium stearate 3.0 (b) Tablet
II mg/tablet Cyclopenta[g]quinazoline salt 50 Lactose Ph.Eur. 223.75
Croscarmellose sodium 6.0 Maize starch 15.0 Polyvinylpyrrolidone
(5% w/v paste) 2.25 Magnesium stearate 3.0 (c) Tablet III mg/tablet
Cyclopenta[g]quinazoline salt 1.0 Lactose Ph.Eur. 93.25 Croscarmellose
sodium 4.0 Maize starch paste (5% w/v paste) 0.75 Magnesium stearate
1.0 (d) Capsule mg/capsule Cyclopenta[g]quinazoline salt 10.0 Lactose
Ph.Eur. 488.5 Magnesium stearate 1.5 (e) Injection I (50 mg/ml)
Cyclopenta[g]quinazoline salt 5.0% w/v 1 M Sodium hydroxide solution
15.0% v/v 0.1 M Hydrochloric acid (to adjust pH to 7.6) Polyethylene
glycol 400 4.5% w/v Water for injection to 100% (f) Injection II
(10 mg/ml) Cyclopenta[g]quinazoline salt 1.0% w/v Sodium phosphate
BP 3.6% w/v 0.1 M Sodium hydroxide solution 15.0% v/v Water for
injection to 100% (1 mg/ml, (g) Injection III buffered to pH 6)
Cyclopenta[g]quinazoline salt 0.1% w/v Sodium phosphate BP 2.26%
w/v Citric acid 0.38% w/v Polyethylene glycol 400 3.5% w/v Water
for injection to 100%
The above formulations may be prepared by conventional procedures
well known in the pharmaceutical art. The tablets (a) to (c) may
be enteric coated by conventional means, for example with a coating
of cellulose acetate phthalate.
TABLE-US-00003 TABLE 1 Activity of 2-substituted quinazolines and
cyclopenta[g]quinazolines in human A431 and A431-FBP cell lines
grown in 20 nM folate (RSLV) Inhibition of cell growth, IC.sub.50,
.mu.M Inhibition of cell growth, IC.sub.50, .mu.M 20 nM LV 20 nM
LV A431 + 1 .mu.M FA A431-FBP A431-FBP + 1 .mu.M FA (fold increased
IC.sub.50 in (fold increased sensitivity (fold increased IC.sub.50
in A431 presence of folic acid) compared with A431) presence of
folic acid) CB30195 0.4 .+-. 0.14 0.37 .+-. 0.14 0.17 .+-. 0.065
0.23 .+-. 0.87 (1) (1) CB300612 2.2 .+-. 0.78 1.9 .+-. 0.65 1.2
.+-. 0.17 1.3 .+-. 0.23 (1) (2) (1) CB300604 3.7 .+-. 0.71 3.4 .+-.
0.91 0.28 .+-. 0.057 1.2 .+-. 0.59 (1) (13) (4) ZD9331 0.082 .+-.
0.042 0.067 .+-. 0.029 0.018 .+-. 0.0097 0.034 .+-. 0.0087 (1) (4)
(2) CB300512 -- -- -- -- CB300533 -- -- -- -- CB300395 0.72 .+-.
0.18 0.72 .+-. 0.12 0.47 .+-. 0.20 0.50 .+-. 0.17 (1) (2) (1) CB300635
9.5 .+-. 5.1 9.7 .+-. 5.4 4.1 .+-. 2.0 4.3 .+-. 2.0 (1) (2) (1)
CB300616 5.9 .+-. 1.0 6.2 .+-. 1.6 4.6 .+-. 0.40 4.7 .+-. 1.1 (1)
(1) (1) CB300638 (RS) 1.4 .+-. 0.23 1.4 .+-. 0.25 0.0065 .+-. 0.0001
0.87 .+-. 0.29 (1) (220) (130) CB300944 (RS) 23, 27 22, 25 8.3 .+-.
0.64 7.1 .+-. 1.0 (1) (3) (1) CB300945 (RS) 9.8 .+-. 3.4 9.3 .+-.
3.5 0.0021 .+-. 0.0011 6.5 .+-. 0.86 (1) (4700) (3100) CB300960
(R,S) 4.5 4.3 0.028 5.1 (1) (180)
TABLE-US-00004 TABLE 2 Activity of 2-substituted quinazolines and
cyclopenta[g]quinazolines in human A431 and A431-FBP cell lines
grown in 1 nM folate (RSLV) Inhibition of cell growth, IC.sub.50,
.mu.M Inhibition of cell growth, IC.sub.50, .mu.M 1 nM LV 1 nM LV
A431 + 1 .mu.M FA A431-FBP A431-FBP + 1 .mu.M FA (fold increased
IC.sub.50 in (fold increased sensitivity (fold increased IC.sub.50
in A431 presence of folic acid) compared with A431) presence of
folic acid) CB30195 0.25 .+-. 0.13 0.21 .+-. 0.078 0.10 .+-. 0.032
0.22 .+-. 0.085 (1) (3) (2) CB300612 1.8 .+-. 0.91 1.5 .+-. 0.51
1.8 .+-. 0.68 2.9 .+-. 0.55 (1) (1) (1) CB300604 1.6 .+-. 0.36 2.0
.+-. 0.49 0.50 .+-. 0.015 1.8 .+-. 0.058 (1) (3) (4) ZD9331 0.061
.+-. 0.014 0.056 .+-. 0.025 0.0088 .+-. 0.0052 0.027 .+-. 0.0076
(1) (7) (3) CB300512 -- -- -- -- CB300533 -- -- -- -- CB300395 0.70
.+-. 0.072 0.74 .+-. 0.053 0.43 .+-. 0.36 0.54 .+-. 0.34 (1) (2)
(1) CB300635 6.1 .+-. 1.3 6.7 .+-. 1.9 2.7 .+-. 0.87 3.3 .+-. 1.5
(1) (2) (1) CB300616 4.9 .+-. 2.0 5.2 .+-. 2.1 5.5 .+-. 3.5 5.6
.+-. 3.0 (1) (1) (1) CB300638 (RS) 1.2 .+-. 0.21 0.98 .+-. 0.23
0.0072 .+-. 0.001 0.61 .+-. 0.012 (1) (170) (85) CB300944 (RS) 24
.+-. 3.6 24 .+-. 2.9 9.1 .+-. 0.83 12 .+-. 2.1 (1) (3) (1) CB300945
(RS) 7.2 .+-. 3.6 7.3 .+-. 3.3 0.0019 .+-. 0.0006 5.7 .+-. 1.3 (3800)
(3100)
TABLE-US-00005 TABLE 3 Activity of 2-substituted quinazolines and
cyclopenta[g]quinazolines in human KB cells grown in 1 and 20 nM
folate (RS LV) Inhibition of cell growth, IC.sub.50, .mu.M Inhibition
of cell growth, IC.sub.50, .mu.M 1 nM LV 20 nM LV KB + 1 .mu.M FA
KB + 1 .mu.M FA (fold increased IC.sub.50 in (fold increased IC.sub.50
in KB presence of folic acid) KB presence of folic acid) CB30195
0.0053 .+-. 0.0006 0.18 .+-. 0.012 0.027 .+-. 0.002 0.15 .+-. 0.015
(34) (6) CB300612 0.97 .+-. 0.20 2.2 .+-. 0.35 1.7 .+-. 0.20 2.0
.+-. 0.25 (2) (1) CB300604 0.0061 .+-. 0.00095 0.69 .+-. 0.08 0.035
.+-. 0.005 0.65 .+-. 0.04 (120) (20) ZD9331 0.0021 .+-. 0.0013 0.00641
.+-. 0.0035 0.0036 .+-. 0.0021 0.012 .+-. 0.005 (3) (3) CB300512
-- -- -- -- CB300533 -- -- -- -- CB300395 0.063 .+-. 0.081 0.23
.+-. 0.05 0.065 .+-. 0.0092 0.17 .+-. 0.032 (4) (3) CB300635 2.8
.+-. 1.1 3.8 .+-. 0.6 3.2 .+-. 0.6 4.4 .+-. 0.25 (1) (1) CB300616
0.0037 .+-. 0.0018 0.58 .+-. 0.05 0.008 .+-. 0.00072 0.59 .+-. 0.19
(160) (74) CB300638 (RS) 0.0079 .+-. 0.001 0.61 .+-. 0.012 0.0053
.+-. 0.0025 0.76 .+-. 0.17 (76) (140) CB300944 (RS) 19 .+-. 0 19
.+-. 1.5 19 .+-. 0.58 19 .+-. 1.2 (1) (1) CB300945 (RS) 0.0034 .+-.
0.0007 7.6 .+-. 1.3 0.0034 .+-. 0.0009 7.3 .+-. 2.0 (2200) (2100)
TABLE-US-00006 TABLE 4 Structures of the compounds tested--Comparative
compounds ##STR00009## ZD9331, R = Me CB300512, R = NH.sub.2 CB300533,
R = CH.sub.2OH ##STR00010## CB300395, R = Me CB300635, R = NH.sub.2
CB300616, R = CH.sub.2OH ##STR00011## CB30195, R = Me CB300612,
R = NH.sub.2 CB300604, R = CH.sub.2OH
TABLE-US-00007 TABLE 5 Structures of the compounds tested--Compounds
of the invention ##STR00012## CB300945 ##STR00013## CB300638 ##STR00014##
CB300944 ##STR00015## CB300960
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