U.S. patent application number 11/557511 was filed with the patent office on 2007-04-19 for benzo[f]isoindole derivatives with affinity to the ep4 receptor.
Invention is credited to Miles Stuart Congreve, Gerard Martin Paul Giblin, Andrew McMurtrie Mason, Neil Derek Miller, Susan Roomans, Ann Louise Walker.
Application Number | 20070088068 11/557511 |
Document ID | / |
Family ID | 9908451 |
Filed Date | 2007-04-19 |
United States Patent
Application |
20070088068 |
Kind Code |
A1 |
Congreve; Miles Stuart ; et
al. |
April 19, 2007 |
Benzo[F]Isoindole Derivatives With Affinity To The EP4 Receptor
Abstract
A compound of formula (I) ##STR1## and processes for the
preparation thereof.
Inventors: |
Congreve; Miles Stuart;
(Cambridge, GB) ; Giblin; Gerard Martin Paul;
(Welwyn, GB) ; Mason; Andrew McMurtrie;
(Stevenage, GB) ; Miller; Neil Derek; (Stevenage,
GB) ; Roomans; Susan; (Stevenage, GB) ;
Walker; Ann Louise; (Stevenage, GB) |
Correspondence
Address: |
GLAXOSMITHKLINE;CORPORATE INTELLECTUAL PROPERTY, MAI B475
FIVE MOORE DR., PO BOX 13398
RESEARCH TRIANGLE PARK
NC
27709-3398
US
|
Family ID: |
9908451 |
Appl. No.: |
11/557511 |
Filed: |
November 8, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10467487 |
May 10, 2004 |
7166631 |
|
|
PCT/GB02/00522 |
Feb 7, 2002 |
|
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11557511 |
Nov 8, 2006 |
|
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Current U.S.
Class: |
514/379 ;
548/241 |
Current CPC
Class: |
A61P 15/00 20180101;
A61P 9/10 20180101; A61P 19/04 20180101; C07D 209/64 20130101; A61P
29/00 20180101; C07D 209/66 20130101; A61P 19/06 20180101; A61P
25/06 20180101; A61P 35/00 20180101; A61P 19/02 20180101; A61P
29/02 20180101; A61P 43/00 20180101; A61P 21/00 20180101; A61P
25/04 20180101; A61P 31/12 20180101; A61P 31/16 20180101; A61P 1/00
20180101 |
Class at
Publication: |
514/379 ;
548/241 |
International
Class: |
A61K 31/42 20060101
A61K031/42; C07D 261/20 20060101 C07D261/20 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 9, 2001 |
GB |
0103269.7 |
Claims
1.-13. (canceled)
14. A process for the preparation of
[4-(4,9-dipropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceti-
c acid comprising reacting
[4-(4,9-dipropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceta-
te with a reducing agent, and thereafter separating the isomers and
deprotecting the compound so formed.
15. A process according to claim 1 in which the reducing agent is
zinc in acetic acid.
16. A process according to claim 1 in which the reducing agent is
sodium borohydride.
17. A process according to claim 1 in which the reaction is
performed under reflux.
18. A process according to claim 1 in which the deprotection step
comprises treatment with an aqueous base.
19. A process according to claim 1 in which the deprotection step
comprises treatment with aqueous potassium carbonate.
Description
[0001] This invention relates to naphthalene derivatives, to
processes for their preparation, to pharmaceutical compositions
containing them and to their use in medicine.
[0002] The EP4 receptor is a 7-transmembrane receptor and its
natural ligand is the prostaglandin PGE.sub.2. PGE.sub.2 also has
affinity for the other EP receptors (types EP1, EP2 and EP3). The
EP4 receptor is associated with smooth muscle relaxation,
inflammation, lymphocyte differentiation, bone metabolism
processes, allergic activities, promotion of sleep, renal
regulation and gastric or enteric mucus secretion. We have now
found a novel group of compounds which bind with high affinity to
the EP4 receptor.
[0003] Compounds exhibiting EP4 binding activity have been
described in, for example, WO00/18744, WO00/03980, WO00/15608,
WO0016760, WO00/21532, WO98/55468, EP0855389 and EP0985663.
GB2330307 describes the use of EP4 antagonists in the treatment of
conditions with accelerated bone resorption. Derivatives of
indoprofen, such as
[4-(1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-2-propionic
acid, sodium salt shown below, have been described by Rufer et. al.
In Eur. J. Med. Chem.--Chimica Therapeutica, 1978, 13, no 2, pg
193-198. ##STR2##
[0004] Accordingly, the present invention provides a compound of
formula (I) ##STR3## wherein [0005] R.sup.1 and R.sup.3 are the
same or different and represent .dbd.O, hydrogen, C.sub.1-6alkyl,
C.sub.1-6dialkyl , .dbd.CHC.sub.1-C.sub.5alkyl, .dbd.S, or a 5- or
6-membered aryl; [0006] R.sup.4 to R.sup.9 are the same or
different and represent hydrogen, C.sub.1-6alkoxy, OCF.sub.3,
OCH.sub.2CF.sub.3, O-cyclopropyl, OCH.sub.2-cyclopropyl,
C.sub.1-C.sub.6alkyl, S-alkyl, NR.sub.2.sup.10 where R.sup.10 is
hydrogen or C.sub.1-6alkyl, halogen, NO.sub.2, OH,
CH.sub.2OC.sub.1-C.sub.6alkyl, CH.sub.2OH, or CF.sub.3; [0007]
Q.sup.1 is hydrogen, C.sub.1-6alkyl, C.sub.1-6dialkyl,
C.sub.1-6alkoxy, NHAc, NR.sub.2.sup.10 where R.sup.10 is hydrogen
or C.sub.1-6alkyl, difluoro, fluoro, .dbd.O, or OH; [0008] Q.sup.2,
Q.sup.3, Q.sup.4 and Q.sup.5 are the same or different and
represent hydrogen, C.sub.1-6alkoxy, OCF.sub.3, OCH.sub.2CF.sub.3,
O-cyclopropyl, OCH.sub.2-cyclopropyl, C.sub.1-C.sub.6alkyl,
S-alkyl, NR.sub.2.sup.10 where R.sup.10 is hydrogen or
C.sub.1-6alkyl, halogen, NO.sub.2, OH,
CH.sub.2OC.sub.1-C.sub.6alkyl, CH.sub.2OH, or a 5- or 6-membered
aryl; [0009] with the proviso that the compounds
[4-(1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-2-propionic
acid, sodium salt and
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid are excluded; [0010] and pharmaceutically acceptable
derivatives thereof.
[0011] By pharmaceutically acceptable derivative is meant any
pharmaceutically acceptable salt, solvate or ester, or salt or
solvate of such ester of the compounds of formula (I), or any other
compound which upon administration to the recipient is capable of
providing (directly or indirectly) a compound of formula (I) or an
active metabolite or residue thereof.
[0012] It will be appreciated by those skilled in the art that the
compounds of formula (I) may be modified to provide
pharmaceutically acceptable derivatives thereof at any of the
functional groups in the compounds, and that the compounds of
formula (I) may be derivatised at more than one position.
[0013] It will be appreciated that, for pharmaceutical use, the
salts referred to above will be the pharmaceutically acceptable
salts, but other salts may find use, for example in the preparation
of compounds of formula (I) and the pharmaceutically acceptable
salts thereof.
[0014] Pharmaceutically acceptable salts include those described by
Berge, Bighley and Monkhouse, J. Pharm. Sci., 1977, 66, 1-19.
Suitable pharmaceutically acceptable salts of the compounds of
formula (I) include acid addition salts formed with inorganic or
organic acids, preferably inorganic acids, e.g. hydrochlorides,
hydrobromides and sulphates. Further representative examples of
pharmaceutically acceptable salts include those formed from acetic,
maleic, fumaric, benzoic, ascorbic, pamoic, succinic,
bismethylenesalicylic, methanesulfonic, ethanedisulfonic,
propionic, tartaric, salicylic, citric, gluconic, aspartic,
stearic, palmitic, itaconic, glycolic, p-aminobenzoic, glutamic,
benzenesulfonic, cyclohexylsulfamic, phosphoric and nitric acids.
Further representative examples of pharmaceutically acceptable
salts include alkali metal salts, formed from the addition of
alkali metal bases, such as alkali metal hydroxides e.g. sodium
salts.
[0015] It will be appreciated that the compound of formula (I) may
be produced in vivo by metabolism of a suitable prodrug. Such
prodrugs may be for example physiologically acceptable
metabolically labile esters of compounds of the general formula
(I). These may be formed by esterification of the carboxylic acid
group in the parent compound of general formula (I) with, where
appropriate, prior protection of any other reactive groups present
in the molecule followed by deprotection if required. Examples of
such metabolically labile esters include C.sub.1-4alkyl esters e.g.
methyl ethyl or t-butyl esters esters, C.sub.3-6 alkenyl esters
e.g. allyl substituted or unsubstituted aminoalkyl esters (e.g.
aminoethyl, 2-(N,N-diethylamino) ethyl, or 2-(4-morpholino)ethyl
esters or acyloxyalkyl esters such as, acyloxymethyl or
1-acyloxyethyl e.g. pivaloyloxymethyl, 1-pivaloyloxyethyl,
acetoxymethyl, 1-
acetoxyethyl,1-(1-methoxy-1-methyl)ethylcarbonyloxyethyl,
1-benzoyloxyethyl, isopropoxycarbonyloxymethyl,
1-isopropoxycarbonyloxyethyl, cyclohexylcarbonyloxymethyl,
1-cyclohexylcarbonyloxyethyl ester, cyclohexyloxycarbonyloxymethyl,
1-cyclohexyloxycarbonyloxyethyl,
1-(4-tetrahydropyranyloxy)carbonyloxyethyl or
1-(4-tetrahydropyranyl)carbonyloxyethyl.
[0016] As used herein, the term halogen atom includes fluorine, and
more especially chlorine, bromine or iodine.
[0017] The term C.sub.1-6alkyl, C.sub.1-6alkoxy or
.dbd.CHC.sub.1-5alkyl as used herein includes straight chain and
branched chain alkyl or alkoxy groups containing 1 to 6 carbon
atoms, and in particular includes methyl, ethyl, n-propyl and
i-propyl or methoxy, ethoxy, i-propoxy, n-propoxy, n-butyloxy or
n-hexyloxy.
[0018] The term 5-membered aryl as used herein means an aryl
selected from the following: ##STR4##
[0019] The term 6- membered aryl as used herein means an aryl
selected from: ##STR5##
[0020] A preferred subgroup of compounds of formula (I) include the
compounds wherein [0021] R.sup.1 is .dbd.O or hydrogen; [0022]
R.sup.3 is .dbd.O, hydrogen, C.sub.1-6alkyl, C.sub.1-6dialkyl, or a
5- or 6-membered aryl; [0023] R.sup.4 and R.sup.9 are the same or
different and represent hydrogen or C.sub.1-6alkoxy; [0024] R.sup.5
and R.sup.8 are hydrogen, or CF.sub.3; [0025] R.sup.6 and R.sup.7
are the same or different and represent hydrogen, C.sub.1-6alkyl,
[0026] C.sub.1-6alkoxy, halogen, NO.sub.2, or CF.sub.3; [0027]
Q.sup.1 is hydrogen, C.sub.1-6alkyl, C.sub.1-6alkoxy, NHAc, or
NR.sub.2.sup.10 where R.sup.10 is hydrogen or C.sub.1-6alkyl;
[0028] Q.sup.2, Q.sup.3, Q.sup.4 and Q.sup.5 are the same or
different and represent hydrogen, C.sub.1-6alkyl, C.sub.1-6alkoxy,
halogen, or a 5- or 6-membered aryl; [0029] with the proviso that
the compounds
[4-(1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-2-propionic
acid, sodium salt and
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid are excluded; [0030] and pharmaceutically acceptable
derivatives thereof.
[0031] R.sup.1 is preferably .dbd.O.
[0032] R.sup.3 is aptly selected from methyl, dimethyl, or
2-furanyl. R.sup.3 is preferably .dbd.O or hydrogen, and is more
preferably hydrogen.
[0033] R.sup.4 and R.sup.9 are each suitably hydrogen, methoxy,
ethoxy, i-propoxy, n-propoxy, n-butyloxy or n-hexyloxy. Suitably at
least one of R.sup.4 and R.sup.9 represents C.sub.1-6alkoxy when
Q.sup.1 is methyl. Preferably R.sup.4 and R.sup.9 are both
C.sub.1-6alkoxy, eg ethoxy.
[0034] R.sup.6 and R.sup.7 are suitably hydrogen, methyl, methoxy,
chlorine, bromine, iodine, NO.sub.2, or CF.sub.3. Preferably
R.sup.6 and R.sup.7 are both hydrogen.
[0035] Q.sup.1 is suitably hydrogen, methyl, ethyl, NHAc, NH.sub.2
or methoxy. Q.sup.1 is preferably hydrogen.
[0036] Q.sup.2, Q.sup.3, Q.sup.4 and Q.sup.5 are each suitably
hydrogen, methyl, methoxy, chlorine, bromine, iodine, 2-thiophenyl,
3-thiophenyl, 2-furanyl, 3-furanyl, or phenyl. Preferably Q.sup.2,
Q.sup.3, Q.sup.4 and Q.sup.5 are all hydrogen.
[0037] A further preferred group of compounds of formula (I) are
those wherein R.sup.1 is .dbd.O; R.sup.3 is methyl, dimethyl,
2-furanyl, preferably .dbd.O or hydrogen, and is more preferably
hydrogen; R.sup.4 and R.sup.9 are each hydrogen, methoxy, ethoxy,
i-propoxy, n-propoxy, n-butyloxy or n-hexyloxy, preferably R.sup.4
and R.sup.9 are both C.sub.1-6alkoxy, eg ethoxy; R.sup.5 and
R.sup.8 are hydrogen; R.sup.6 and R.sup.7 are hydrogen, methyl,
methoxy, chlorine, bromine, iodine, NO.sub.2, or CF.sub.3,
preferably R.sup.6 and R.sup.7 are both hydrogen; [0038] Q.sup.1 is
suitably hydrogen, methyl, ethyl, NHAc, NH.sub.2 or methoxy,
preferably hydrogen; Q.sup.2, Q.sup.3, Q.sup.4 and Q.sup.5 are each
suitably hydrogen, methyl, methoxy, chlorine, bromine, iodine,
2-thiophenyl, 3-thiophenyl, 2-furanyl, 3-furanyl, or phenyl,
preferably Q.sup.2, Q.sup.3, Q.sup.4 and Q.sup.5 are all hydrogen;
[0039] with the proviso that the compounds
[4-(1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-2-propionic
acid, sodium salt and
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid are excluded; [0040] and pharmaceutically acceptable
derivatives thereof.
[0041] It is to be understood that the present invention
encompasses all isomers of the compounds of formula (I) and their
pharmaceutically acceptable derivatives, including all geometric,
tautomeric and optical forms, and mixtures thereof (e.g. racemic
mixtures).
[0042] Preferred compounds of the present invention include: [0043]
[4-(4-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0044]
[4-(4,9-dimethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceti-
c acid; [0045]
[4-(4-methoxy-9-ethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-
acetic acid; [0046]
[4-(4-methoxy-9-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl-
] acetic acid; [0047]
[4-(4-methoxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl] acetic acid; [0048]
[4-(4-ethoxy-9-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-
acetic acid; [0049]
[4-(4-ethoxy-9-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]
acetic acid; [0050]
[4-(4-ethoxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl] acetic acid; [0051]
[4-(4-ethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0052]
[4-(4-propoxy-9-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl-
] acetic acid; [0053]
[4-(4-propoxy-9-ethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]
acetic acid; [0054]
[4-(4,9-dipropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceti-
c acid; [0055]
[4-(9-isopropoxy4-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl] acetic acid; [0056]
[4-(4-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0057]
[4-(4-isopropoxy-9-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl] acetic acid; [0058]
[4-(4-isopropoxy-9-ethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl] acetic acid; [0059]
[4-(4-isopropoxy-9-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl] acetic acid; [0060]
[4-(4,9-di-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]a-
cetic acid; [0061]
[4-(4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0062]
[4-(9-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0063]
[4-(9-ethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0064]
[4-(9-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0065]
[4-(9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0066]
[4-(4,9-diethoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etic acid; [0067]
[4-(4-methoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceti-
c acid; [0068]
[4-(4,9-dimethoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]a-
cetic acid; [0069]
[4-(4-methoxy-9-ethoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl] acetic acid; [0070]
[4-(4-methoxy-9-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)
phenyl]acetic acid; [0071]
[4-(4-methoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl-
) phenyl]acetic acid; [0072]
[4-(4-ethoxy-9-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)
phenyl] acetic acid; [0073]
[4-(4-ethoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-
phenyl] acetic acid; [0074]
[4-(4-ethoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0075]
[4-(4,9-dipropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]
acetic acid; [0076]
[4-(9-isopropoxy4-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)
phenyl]acetic acid; [0077]
[4-(4-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceti-
c acid; [0078]
[4-(4,9-di-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl] acetic acid; [0079]
[4-(4-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etic acid; [0080]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-2-pro-
pionic acid; [0081]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-2-but-
yric acid; [0082]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-2-(N--
acetylamino)acetic acid; [0083]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-2-ami-
noacetic acid; [0084]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-2-met-
hoxyacetic acid; [0085]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-3-methylphen-
yl] acetic acid; [0086]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-3-methoxyphe-
nyl] acetic acid; [0087]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-3,5-dimethyl-
phenyl] acetic acid; [0088]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-3-iodophenyl-
]acetic acid; [0089]
[3-chloro4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-phen-
yl] acetic acid; [0090]
[3-bromo-4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-phen-
yl] acetic acid; [0091]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-2-methylphen-
yl] acetic acid; [0092]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-2-methoxyphe-
nyl] acetic acid; [0093]
[2-chloro4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-phen-
yl] acetic acid; [0094]
[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-2-iodophenyl-
]acetic acid; [0095]
[2-bromo-4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-phen-
yl] acetic acid; [0096]
[4-(6,7-dichloro-4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-
phenyl] acetic acid; [0097]
[4-(4,9-diethoxy-6-methyl-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl] acetic acid; [0098]
[4-(4,9-diethoxy-7-methyl-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl] acetic acid; [0099]
[4-(7-bromo-4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)pheny-
l] acetic acid; [0100]
[4-(4,9-diethoxy-7-iodo-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl-
]acetic acid; [0101]
[4-(6-bromo-4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)pheny-
l] acetic acid; [0102]
[4-(4,9-diethoxy-6-iodo-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl-
]acetic acid; [0103]
[4-(4,9-diethoxy-3,3-dimethyl-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-
phenyl] acetic acid; [0104]
[4-(4,9-diethoxy-3-methyl-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl] acetic acid; [0105]
[4-(4,9-diethoxy-6-nitro-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)pheny-
l]acetic acid; [0106]
[4-(4,9-diethoxy-7-nitro-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)pheny-
l]acetic acid; [0107] [4-(4,
9-diethoxy-6-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]
acetic acid; [0108]
[4-(4,9-diethoxy-7-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl] acetic acid; [0109]
[4-(6-chloro-4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl] acetic acid; [0110]
[4-(7-chloro-4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl] acetic acid; [0111]
[4-(4,9-dibutoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0112]
[4-(4,9-dihexyloxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acet-
ic acid; [0113]
[4-(4-hexyloxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetic acid; [0114]
[4-(9-hexyloxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetic acid; [0115]
[4-(4,9-dibutoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etic acid; [0116]
[4-(4,9-dihexyloxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-
acetic acid; [0117]
[4-(4-butoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-
phenyl]acetic acid; [0118]
[4-(4,9-diethoxy-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0119]
[4-(9-ethoxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol--
2-yl)phenyl]acetic acid; [0120] and pharmaceutically acceptable
derivatives thereof.
[0121] Particularly preferred compounds according to the invention
are: [0122]
[4-(4,9-dimethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetic acid; [0123]
[4-(4,9-diethoxy-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0124]
[4-(4,9-di-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl-
)phenyl]acetic acid; [0125]
[4-(4,9-dipropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceti-
c acid; [0126]
[4-(4,9-dibutoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0127]
[4-(4,9-dihexyloxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acet-
ic acid; [0128]
[4-(4-ethoxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetic acid; [0129]
[4-(9-ethoxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetic acid; [0130]
[4-(9-isopropoxy-4-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetic acid; [0131]
[4-(4-isopropoxy-9-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetic acid; [0132]
[4-(4-hexyloxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetic acid; [0133]
[4-(9-hexyloxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)
phenyl]acetic acid; [0134]
[4-(4-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid; [0135]
[4-(4,9-diethoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etic acid; [0136]
[4-(4,9-di-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetic acid; [0137]
[4-(4,9-dipropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]a-
cetic acid; [0138]
[4-(4,9-dibutoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etic acid; [0139]
[4-(4,9-dihexyloxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-
acetic acid; [0140]
[4-(4-ethoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-
phenyl]acetic acid; [0141]
[4-(9-isopropoxy-4-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl-
)phenyl]acetic acid; [0142]
[4-(4-butoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-
phenyl]acetic acid; [0143] and pharmaceutically acceptable
derivatives thereof.
[0144] It is to be understood that the present invention covers all
combinations of particular and preferred groups as described herein
above.
[0145] Since the compounds of the present invention, in particular
compounds of formula (I), are intended for use in pharmaceutical
compositions, it will be understood that they are each provided in
substantially pure form, for example at least 50% pure, more
suitably at least 75% pure and preferably at least 95% pure (% are
on a wt/wt basis). Impure preparations of the compounds of formula
(I) may be used for preparing the more pure forms used in the
pharmaceutical compositions. Although the purity of intermediate
compounds of the present invention is less critical, it will be
readily understood that the substantially pure form is preferred as
for the compounds of formula (I). Preferably, whenever possible,
the compounds of the present invention are obtained in crystalline
form.
[0146] When some of the compounds of this invention are allowed to
crystallise or are recrystallised from organic solvents, solvent of
crystallisation may be present in the crystalline product. This
invention includes within its scope such solvates. Similarly, some
of the compounds of this invention may be crystallised or
recrystallised from solvents containing water. In such cases water
of hydration may be formed. This invention includes within its
scope stoichiometric hydrates as well as compounds containing
variable amounts of water that may be produced by processes such as
lyophilisation. In addition, different crystallisation conditions
may lead to the formation of different polymorphic forms of
crystalline products. This invention includes within its scope all
polymorphic forms of the compounds of formula (I).
[0147] The compounds of the invention bind to the EP4 receptor and
are therefore useful in treating EP4 receptor mediated
diseases.
[0148] In view of their ability to bind to the EP4 receptor, the
compounds of the invention are useful in the treatment of the
disorders that follow. Thus, the compounds of formula (I) are
useful as analgesics. For example they are useful in the treatment
of chronic articular pain (e.g. rheumatoid arthritis,
osteoarthritis, rheumatoid spondylitis, gouty arthritis and
juvenile arthritis) including the property of disease modification
and joint structure preservation; musculoskeletal pain; lower back
and neck pain; sprains and strains; neuropathic pain;
sympathetically maintained pain; myositis; pain associated with
cancer and fibromyalgia; pain associated with migraine; pain
associated with influenza or other viral infections, such as the
common cold; rheumatic fever; pain associated with functional bowel
disorders such as non-ulcer dyspepsia, non-cardiac chest pain and
irritable bowel syndrome; pain associated with myocardial ischemia;
post operative pain; headache; toothache; and dysmenorrhea.
[0149] The compounds of the invention are particularly useful in
the treatment of neuropathic pain. Neuropathic pain syndromes can
develop following neuronal injury and the resulting pain may
persist for months or years, even after the original injury has
healed. Neuronal injury may occur in the peripheral nerves, dorsal
roots, spinal cord or certain regions in the brain. Neuropathic
pain syndromes are traditionally classified according to the
disease or event that precipitated them. Neuropathic pain syndromes
include: diabetic neuropathy; sciatica; non-specific lower back
pain; multiple sclerosis pain; fibromyalgia; HIV-related
neuropathy; post-herpetic neuralgia; trigeminal neuralgia; and pain
resulting from physical trauma, amputation, cancer, toxins or
chronic inflammatory conditions. These conditions are difficult to
treat and although several drugs are known to have limited
efficacy, complete pain control is rarely achieved. The symptoms of
neuropathic pain are incredibly heterogeneous and are often
described as spontaneous shooting and lancinating pain, or ongoing,
burning pain. In addition, there is pain associated with normally
non-painful sensations such as "pins and needles" (paraesthesias
and dysesthesias), increased sensitivity to touch (hyperesthesia),
painful sensation following innocuous stimulation (dynamic, static
or thermal allodynia), increased sensitivity to noxious stimuli
(thermal, cold, mechanical hyperalgesia), continuing pain sensation
after removal of the stimulation (hyperpathia) or an absence of or
deficit in selective sensory pathways (hypoalgesia).
[0150] The compounds of formula (I) are also useful in the
treatment of inflammation, for example in the treatment of skin
conditions (e.g. sunburn, burns, eczema, dermatitis, psoriasis);
ophthalmic diseases such as glaucoma, retinitis, retinopathies,
uveitis and of acute injury to the eye tissue (e.g.
conjunctivitis); lung disorders (e.g. asthma, bronchitis,
emphysema, allergic rhinitis, respiratory distress syndrome pigeon
fancier's disease, farmer's lung, COPD); gastrointestinal tract
disorders (e.g. aphthous ulcer, Crohn's disease, atopic gastritis,
gastritis varialoforme, ulcerative colitis, coeliac disease,
regional ileitis, irritable bowel syndrome, inflammatory bowel
disease, gastrointestinal reflux disease); organ transplantation;
other conditions with an inflammatory component such as vascular
disease, migraine, periarteritis nodosa, thyroiditis, aplastic
anaemia, Hodgkin's disease, sclerodoma, myaesthenia gravis,
multiple sclerosis, sorcoidosis, nephrotic syndrome, Bechet's
syndrome, polymyositis, gingivitis, myocardial ischemia, pyrexia,
systemic lupus erythematosus, polymyositis, tendinitis, bursitis,
and Sjogren's syndrome.
[0151] The compounds of formula (I) are also useful in the
treatment of immunological diseases such as autoimmune diseases,
immunological deficiency diseases or organ transplantation. The
compounds of formula (I) are also effective in increasing the
latency of HIV infection.
[0152] The compounds of formula (I) are also useful in the
treatment of diseases of abnormal platelet function (e.g. occlusive
vascular diseases).
[0153] The compounds of formula (I) are also useful for the
preparation of a drug with diuretic action.
[0154] The compounds of formula (I) are also useful in the
treatment of impotence or erectile dysfunction.
[0155] The compounds of formula (I) are also useful in the
treatment of bone disease characterised by abnormal bone metabolism
or resorption such as osteoporosis (especially postmenopausal
osteoporosis), hyper-calcemia, hyperparathyroidism, Paget's bone
diseases, osteolysis, hypercalcemia of malignancy with or without
bone metastases, rheumatoid arthritis, periodontitis,
osteoarthritis, ostealgia, osteopenia, cancer cacchexia,
calculosis, lithiasis (especially urolithiasis), solid carcinoma,
gout and ankylosing spondylitis, tendinitis and bursitis. In a
further aspect compounds of formula (I) may be useful in inhibiting
bone resorption and/or promoting bone generation.
[0156] The compounds of formula (I) are also useful for attenuating
the hemodynamic side effects of NSAIDs and COX-2 inhibitors.
[0157] The compounds of formula (I) are also useful in the
treatment of cardiovascular diseases such as hypertension or
myocardiac ischemia; functional or organic venous insufficiency;
varicose therapy; haemorrhoids; and shock states associated with a
marked drop in arterial pressure (e.g. septic shock).
[0158] The compounds of formula (I) are also useful in the
treatment of neurodegenerative diseases and neurodegeneration such
as dementia, particularly degenerative dementia (including senile
dementia, Alzheimer's disease, Pick's disease, Huntingdon's chorea,
Parkinson's disease and Creutzfeldt-Jakob disease, ALS, motor
neuron disease); vascular dementia (including multi-infarct
dementia); as well as dementia associated with intracranial space
occupying lesions; trauma; infections and related conditions
(including HIV infection); metabolism; toxins; anoxia and vitamin
deficiency; and mild cognitive impairment associated with agreeing,
particularly Age Associated Memory Impairment.
[0159] The compounds of formula (I) are also useful in the
treatment of neuroprotection and in the treatment of
neurodegeneration following stroke, cardiac arrest, pulmonary
bypass, traumatic brain injury, spinal cord injury or the like.
[0160] The compounds of formula (I) are also useful in the
treatment of tinnitus.
[0161] The compounds of formula (I) are also useful in preventing
or reducing dependence on, or preventing or reducing tolerance or
reverse tolerance to, a dependence--inducing agent. Examples of
dependence inducing agents include opioids (e.g. morphine), CNS
depressants (e.g. ethanol), psychostimulants (e.g. cocaine) and
nicotine.
[0162] The compounds of formula (I) are also useful in the
treatment of complications of Type 1 diabetes (e.g. diabetic
microangiopathy, diabetic retinopathy, diabetic nephropathy,
macular degeneration, glaucoma), nephrotic syndrome, aplastic
anaemia, uveitis, Kawasaki disease and sarcoidosis.
[0163] The compounds of formula (I) are also useful in the
treatment of kidney dysfunction (nephritis, particularly mesangial
proliferative glomerulonephritis, nephritic syndrome), liver
dysfunction (hepatitis, cirrhosis), gastrointestinal dysfunction
(diarrhoea) and colon cancer.
[0164] It is to be understood that reference to treatment includes
both treatment of established symptoms and prophylactic treatment,
unless explicitly stated otherwise.
[0165] According to a further aspect of the invention, we provide a
compound of formula (I) or a pharmaceutically acceptable derivative
thereof for use in human or veterinary medicine.
[0166] According to another aspect of the invention, we provide a
compound of formula (I) or a pharmaceutically acceptable derivative
thereof for use in the treatment of a condition which is mediated
by the action of PGE.sub.2 at EP4 receptors.
[0167] According to a further aspect of the invention, we provide a
method of treating a human or animal subject suffering from a
condition which is mediated by the action of PGE.sub.2 at EP4
receptors which comprises administering to said subject an
effective amount of a compound of formula (I) or a pharmaceutically
acceptable derivative thereof.
[0168] According to a further aspect of the invention we provide a
method of treating a human or animal subject suffering from a pain,
inflammatory, immunological, bone, neurodegenerative or renal
disorder, which method comprises administering to said subject an
effective amount of a compound of formula (I) or a pharmaceutically
acceptable derivative thereof.
[0169] According to another aspect of the invention, we provide the
use of a compound of formula (I) or a pharmaceutically acceptable
derivative thereof for the manufacture of a therapeutic agent for
the treatment of a condition which is mediated by the action of
PGE.sub.2 at EP4 receptors.
[0170] According to another aspect of the invention we provide the
use of a compound of formula (I) or a pharmaceutically acceptable
derivative thereof for the manufacture of a therapeutic agent for
the treatment or prevention of a condition such as a pain,
inflammatory, immunological, bone, neurodegenerative or renal
disorder.
[0171] The compounds of formula (I) and their pharmaceutically
acceptable derivatives are conveniently administered in the form of
pharmaceutical compositions. Such compositions may conveniently be
presented for use in conventional manner in admixture with one or
more physiologically acceptable carriers or excipients.
[0172] Thus, in another aspect of the invention, we provide a
pharmaceutical composition comprising a compound of formula (I) or
a pharmaceutically acceptable derivative thereof adapted for use in
human or veterinary medicine.
[0173] While it is possible for the compounds of formula (I) or a
pharmaceutically acceptable derivative thereof to be administered
as the raw chemical, it is preferable to present it as a
pharmaceutical formulation. The formulations of the present
invention comprise the compounds of formula (I) or a
pharmaceutically acceptable derivative thereof together with one or
more acceptable carriers or diluents thereof and optionally other
therapeutic ingredients. The carrier(s) must be "acceptable" in the
sense of being compatible with the other ingredients of the
formulation and not deleterious to the recipient thereof.
[0174] The formulations include those suitable for oral, parenteral
(including subcutaneous e.g. by injection or by depot tablet,
intradermal, intrathecal, intramuscular e.g. by depot and
intravenous), rectal and topical (including dermal, buccal and
sublingual) administration although the most suitable route may
depend upon for example the condition and disorder of the
recipient. The formulations may conveniently be presented in unit
dosage form and may be prepared by any of the methods well known in
the art of pharmacy. All methods include the step of bringing into
association the compound of formula (I) or a pharmaceutically
acceptable acid addition salt thereof ("active ingredient") with
the carrier which constitutes one or more accessory ingredients. In
general the formulations are prepared by uniformly and intimately
bringing into association the active ingredient with liquid
carriers or finely divided solid carriers or both and then, if
necessary, shaping the product into the desired formulation.
[0175] Formulations of the present invention suitable for oral
administration may be presented as discrete units such as capsules,
cachets or tablets (e.g. chewable tablets in particular for
paediatric administration) each containing a predetermined amount
of the active ingredient; as a powder or granules; as a solution or
a suspension in an aqueous liquid or a non-aqueous liquid; or as an
oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The
active ingredient may also be presented as a bolus, electuary or
paste.
[0176] A tablet may be made by compression or moulding, optionally
with one or more accessory ingredients. Compressed tablets may be
prepared by compressing in a suitable machine the active ingredient
in a free-flowing form such as a powder or granules, optionally
mixed with a binder, lubricant, inert diluent, lubricating, surface
active or dispersing agent. Moulded tablets may be made by moulding
in a suitable machine a mixture of the powdered compound moistened
with an inert liquid diluent. The tablets may optionally be coated
or scored and may be formulated so as to provide slow or controlled
release of the active ingredient therein.
[0177] Formulations for parenteral administration include aqueous
and non-aqueous sterile injection solutions which may contain
anti-oxidants, buffers, bacteriostats and solutes which render the
formulation isotonic with the blood of the intended recipient; and
aqueous and non-aqueous sterile suspensions which may include
suspending agents and thickening agents. The formulations may be
presented in unit-dose or multi-dose containers, for example sealed
ampoules and vials, and may be stored in a freeze-dried
(lyophilised) condition requiring only the addition of a sterile
liquid carrier, for example, water-for-injection, immediately prior
to use. Extemporaneous injection solutions and suspensions may be
prepared from sterile powders, granules and tablets of the kind
previously described.
[0178] Formulations for rectal administration may be presented as a
suppository with the usual carriers such as cocoa butter, hard fat
or polyethylene glycol.
[0179] Formulations for topical administration in the mouth, for
example buccally or sublingually, include lozenges comprising the
active ingredient in a flavoured basis such as sucrose and acacia
or tragacanth, and pastilles comprising the active ingredient in a
basis such as gelatin and glycerin or sucrose and acacia.
[0180] The compounds of the invention may also be formulated as
depot preparations. Such long acting formulations may be
administered by implantation (for example subcutaneously or
intramuscularly) or by intramuscular injection. Thus, for example,
the compounds of the invention may be formulated with suitable
polymeric or hydrophobic materials (for example as an emulsion in
an acceptable oil) or ion exchange resins, or as sparingly soluble
derivatives, for example, as a sparingly soluble salt.
[0181] In addition to the ingredients particularly mentioned above,
the formulations may include other agents conventional in the art
having regard to the type of formulation in question, for example
those suitable for oral administration may include flavouring
agents.
[0182] The EP4 receptor compounds for use in the instant invention
may be used in combination with other therapeutic agents, for
example COX-2 inhibitors, such as celecoxib, rofecoxib, valdecoxib
or parecoxib; 5-lipoxygenase inhibitors; NSAID's, such as
diclofenac, indomethacin, nabumetone or ibuprofen; leukotriene
receptor antagonists; DMARD's such as methotrexate; adenosine A1
receptor agonists; sodium channel blockers, such as lamotrigine;
NMDA receptor modulators, such as glycine receptor antagonists;
gabapentin and related compounds; tricyclic antidepressants such as
amitriptyline; neurone stabilising antiepileptic drugs;
mono-aminergic uptake inhibitors such as venlafaxine; opioid
analgesics; local anaesthetics; 5HT.sub.1 agonists, such as
triptans, for example sumatriptan, naratriptan, zolmitriptan,
eletriptan, frovatriptan, almotriptan or rizatriptan; EP1 receptor
ligands; EP2 receptor ligands; EP3 receptor ligands; EP1
antagonists; EP2 antagonists and EP3 antagonists. When the
compounds are used in combination with other therapeutic agents,
the compounds may be administered either sequentially or
simultaneously by any convenient route.
[0183] The invention thus provides, in a further aspect, a
combination comprising a compound of formula (I) or a
pharmaceutically acceptable derivative thereof together with a
further therapeutic agent or agents.
[0184] The combinations referred to above may conveniently be
presented for use in the form of a pharmaceutical formulation and
thus pharmaceutical formulations comprising a combination as
defined above together with a pharmaceutically acceptable carrier
or excipient comprise a further aspect of the invention. The
individual components of such combinations may be administered
either sequentially or simultaneously in separate or combined
pharmaceutical formulations.
[0185] When a compound of formula (I) or a pharmaceutically
acceptable derivative thereof is used in combination with a second
therapeutic agent active against the same disease, the dose of each
compound may differ from that when the compound is used alone.
Appropriate doses will be readily appreciated by those skilled in
the art.
[0186] A proposed daily dosage of compounds of formula (I) or their
pharmaceutically acceptable salts for the treatment of man is from
0.01 to 10 mg/kg body weight per day and more particularly 0.1 to 3
mg/kg body weight per day, calculated as the free base, which may
be administered as a single or divided dose, for example one to
four times per day The dose range for adult human beings is
generally from 8 to 1000 mg/day, such as from 20 to 800 mg/day,
preferably 35 to 200 mg/day, calculated as the free base.
[0187] The precise amount of the compounds of formula (I)
administered to a host, particularly a human patient, will be the
responsibility of the attendant physician. However, the dose
employed will depend on a number of factors including the age and
sex of the patient, the precise condition being treated and its
severity, and the route of administration.
[0188] The present invention provides a process for preparing
compounds of formula (I) and pharmaceutically acceptable
derivatives thereof.
[0189] Compounds of formula (I) and pharmaceutically acceptable
derivatives thereof may be prepared by any method known in the art
for the preparation of compounds of analogous structure.
[0190] Suitable methods for the preparation of compounds of formula
(I) and pharmaceutically acceptable derivatives thereof are
described below and form a further aspect of the invention. In the
formulae that follow, R.sup.1 to R.sup.10 and Q.sup.1-Q.sup.5 are
as defined in formula (I) above unless otherwise stated.
[0191] According to a first process (A), compounds of formula (I),
where R.sup.1 and R.sup.3 are both .dbd.O and R.sup.4 and R.sup.9
are the same or different and represent C.sub.1-6alkoxy, may be
prepared by reacting a compound of formula (II) ##STR6## with a
4-aminophenylacetic acid of formula (III) ##STR7## in glacial
acetic acid at elevated temperature.
[0192] According to another process (B) compounds of formula (I),
where one of R.sup.1 and R.sup.3 is .dbd.O and the other is
hydrogen and R.sup.4 and R.sup.9 are the same or different and
represent C.sub.1-6alkoxy, may be prepared by reducing a compound
of formula (IV) ##STR8## with a suitable reducing agent, followed
by separation of isomers and deprotection (eg. with aqueous base at
elevated temperature). Suitable reducing agents include zinc in
acetic acid at elevated temperature and sodium borohydride in
methanol followed by trifluoroacetic acid (TFA) and
triethylsilane.
[0193] According to another process (C) compounds of formula (I),
where one of R.sup.1 and R.sup.3 is .dbd.O and the other is
hydrogen and R.sup.4 and R.sup.9 are the same or different and
represent C.sup.1-6alkoxy, may be prepared by reacting a compound
of formula (V) ##STR9## with a 4-aminophenylacetic acid of formula
(III) as defined above in the presence of triethylamine and
dimethylformamide, followed by deprotection (eg. using acetic acid
at elevated temperature).
[0194] According to a further process (D) compounds of formula (I),
where one of R.sup.1 and R.sup.3 is .dbd.O and the other is
hydrogen and one of R.sup.4 and R.sup.9 is C.sub.1-6alkoxy, may be
prepared by reacting a compound of formula (VI) ##STR10## where
R.sup.D is in the -4 or -9 position and is C.sub.1-6 alkoxy, with a
4-aminophenylacetate of formula (VII) ##STR11## in the presence of
sodium triacetoxyborohydride in a suitable solvent, such as
dichloromethane, followed by deprotection (eg. with aqueous base at
elevated temperature).
[0195] According to a further process (E) compounds of formula (I),
where R.sup.1 and R.sup.3 are both hydrogen and R.sup.4 and R.sup.9
are the same or different and represent C.sub.1-6 alkoxy, may be
prepared by reacting a compound of formula (VIII) ##STR12## with a
4-aminophenylacetate of formula (VII) as described above in a
suitable solvent, such as dimethylformamide, at elevated
temperature followed by deprotection (eg. using aqueous base such
as lithium hydroxide in aqueous tetrahydrofuran).
[0196] According to a further process (F) compounds of formula (I),
where R.sup.3 is .dbd.CHC.sub.1-5alkyl, may be prepared by reacting
a compound of formula (IV) as defined above with a Grignard reagent
C.sub.1-C.sub.6alkyl-MgBr under conventional conditions, followed
by separation of isomers and deprotection (eg. with aqueous base at
elevated temperature).
[0197] According to a further process (G) compounds of formula (I),
where R.sup.3 is C.sub.1-6-dialkyl, may be prepared by reacting a
compound of formula (IX) ##STR13## with a 4-aminophenylacetate of
formula (VII) as defined above in the presence of aluminium
trichloride, followed by deprotection (eg. with aqueous base at
elevated temperature).
[0198] According to a further process (H) compounds of formula (I)
prepared according to processes (A) to (G) may be converted into
other compounds of formula (I) using conventional procedures. For
example, compounds of formula (I) where R.sup.3 is C.sub.1-6alkyl,
may be prepared by reducing a compound of formula (I) where R.sup.3
is .dbd.CHC.sub.1-5alkyl, protected at the carboxyl group, with a
suitable reducing agent, such as hydrogen in the presence of a
palladium on carbon catalyst, followed by deprotection (eg. with
aqueous base at elevated temperature). Also, compounds of formula
(I) where R.sup.3 is .dbd.O may be converted into compounds of
formula (I) where R.sup.3 is .dbd.S by conventional methods, for
example using Lawesson's reagent.
[0199] Compounds of formulae (II) to (IX) may be prepared by any
method known in the art for the preparation of compounds of
analogous structure.
[0200] Compounds of formula (II) may, for example be prepared
according to Scheme 1 that follows. ##STR14##
[0201] Compounds of formula (IV) may be prepared by reacting
compounds of formula (II) with a 4-aminophenylacetate of formula
(VII) as defined above in the presence of acetic acid.
[0202] Compounds of formula (V) may, for example be prepared
according to Scheme 2 that follows. ##STR15##
[0203] Compounds of formula (VI) may, for example, be prepared
according to Scheme 3 that follows. ##STR16##
[0204] Compounds of formula (VIII) may be prepared, for example, by
reacting a compound of formula (X) ##STR17## with phosphorous
tribromide in an ether solvent, for example a mixture of diethyl
ether and tetrahydrofuran.
[0205] Compounds of formula (IX) may be prepared by reacting a
compound of formula (XI) with a Grignard reagent R.sup.3-MgBr under
conventional conditions. ##STR18##
[0206] Compounds of formulae (III) and (VII) may be prepared
according to methods known in the art for the preparation of
analogous compounds, for example, compounds where Q.sup.1 is methyl
may be prepared by the method of Takahashi,I et al. Heterocycles
(1996), 43(11), 2343-2346; compounds where Q.sup.1 is ethyl may be
prepared by the method of Kirschenheuter, Gary P et al. in
EP465802; compounds where Q.sup.1 is NHAc may be prepared by the
method described in US3479339; compounds where Q.sup.1 is NH.sub.2
may be prepared by the method of Herbert, Richard B et al. J Chem.
Soc., Perkin Trans. 1 (1992), (1), 109-13; compounds where Q.sup.1
is MeO may be prepared from the corresponding nitro compounds
prepared by the method of Tomioka, Hideo et al. J. Am. Chem. Soc.
(1990), 112(21), 7692-702; compounds where Q.sup.2 is Me or Q.sup.3
is Cl may be prepared by the method described in U.S. Pat No.
3,860,639 (Schultz, Everett M.); compounds where Q.sup.2 is MeO may
be prepared by the method of Nannini, G et al, Arzneim.-Forsch.
(1973), 23(8), 1090-100 by hydrolysis of the ethyl ester; compounds
where Q.sup.2 is Cl may be prepared by the method of Atkinson,
Joseph G et al. Tet Lett. (1979), (31), 2857-60 by reduction of the
corresponding nitro compound; compounds where Q.sup.2 is I may be
prepared by the method of Sindelar, Karel et al. Collect. Czech.
Chem. Commun.(1978), 43(2), 471-97 by reduction of the
corresponding nitro compound; compounds where Q.sup.2 is Br may be
prepared by the method of Sindelar, Karel et al. Collect. Czech.
Chem. Commun.(1978), 43(2), 471-97; compounds where Q3 is Me may be
prepared by the method of Borck, Joachim et al. in ZA 6804711;
compounds where Q.sup.3 is MeO may be prepared by the method of
Gallacher, Gerard et al. Biorg. Amines (1995), 11(1), 49-62 by
reduction of the corresponding nitro compound; compounds where
Q.sup.3 is I may be prepared by the method of Boehm, Marcus F et
al. J Chem. Soc., Chem. Commun. (1991), (1), 52-3; compounds where
Q.sup.3 is Br may be prepared by the method of Figala, Georg et al.
in DE 2746067; compounds where Q.sup.3 and Q.sup.4 are Me may be
prepared by the method of Yost, Yul et al. Org. Prep. Proced. Int.
(1985), 17(4-5), 23949 from the corresponding benzoic acid using
the Arndt-Eistert reaction.
[0207] Certain intermediates described above are novel compounds,
and it is to be understood that all novel intermediates herein form
further aspects of the present invention. Compounds of formula
(II), (V), (VI), (VIII) and (IX) are key intermediates and
represent a particular aspect of the invention. Certain
intermediates, such as compounds of formula (IV), may be prodrugs
of compounds of formula (I).
[0208] Conveniently, compounds of the invention are isolated
following work-up in the form of the free base. Pharmaceutically
acceptable acid addition salts of the compounds of the invention
may be prepared using conventional means. Solvates (e.g. hydrates)
of a compound of the invention may be formed during the work-up
procedure of one of the aforementioned process steps.
[0209] The following Examples which should not be construed as
constituting a limitation thereto are provided to illustrate the
invention.
[0210] .sup.1H NMR spectra were obtained at 400 MHz on a Bruker
DPX400 spectrophotometer. J values are given in Hz. Mass spectra
were obtained on a Micromass series II MS (electrospray positive or
negative). Where HPLC retention times are given as a
characterisation of intermediates or Examples this refers to an HP
1050 or a HP1 100 running a 5.5 minute Gradient: Eluents: A--0.1 %
VN Formic Acid+1 Ommol Ammonium Acetate [0211] B--95% MeCN+0.05% VN
Formic Acid [0212] Flow rate: 3 ml/min [0213] Column: 3.3
cm.times.4.6 mm internal diameter, 3 .mu.m ABZ+PLUS [0214]
Injection Volume: 5 .mu.l [0215] Temperature: Room temperature.
[0216] Gradient: TABLE-US-00001 Time % A % B 0.00 100 0.00 0.70 100
0.00 4.40 0.00 100 5.30 0.00 100 5.50 100 0.00
Intermediate 1
Ethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate
[0217] Sodium (60 g, 2.6 mol) was dissolved in ethanol (1.2 L) and
the mixture was cooled to 40.degree. C. Diethylphthalate (960 ml,
4.83 mol) was added and the mixture heated under nitrogen until the
temperature reached 115.degree. C. Diethyl succinate (211.3 g, 1.21
mol) was added dropwise over 45 min. The reaction was heated at
115.degree. C. for a further 45 min, cooled to room temperature and
poured onto water (1.2 L). Ethyl acetate (1 L) was added and
stirred, the layers were separated and the organics were extracted
with sodium hydroxide solution (2N, 1 L). The combined aqueous was
acidified to pH 3 and the mixture extracted with ethyl acetate
(2.times.1 L). The combined organics were washed with a saturated
solution of sodium hydrogen carbonate (2.times.1.5 L), then brine,
dried (MgSO.sub.4), filtered and the solvent evaporated under
vacuum. The residue was purified using a 2.5 kg Biotage column
eluting with 5% ethyl acetate/hexane to give ethyl
1,4-dihydroxy-2,3-naphthalenedicarboxylate as a white solid, (60 g,
16%). .delta.H CDCl.sub.3 10.44, (2H, s), 8.34, (2H, m), 7.68, (2H,
m), 4.37, (4H, q), 1.37, (6H, t)
Intermediate 2
Ethyl 1,4-diethoxy-2,3-naphthalenedicarboxylate
[0218] Ethyl 1,4-dihydroxy-2,3-naphthalenedicarboxylate (30 g, 98.6
mmol) and potassium carbonate (150 g, 1.09 mmol) were stirred in
acetone (600 ml) under nitrogen. lodoethane (150 g, 0.96 mol) was
added and the mixture was stirred at reflux overnight. The reaction
was cooled, diluted with ethyl acetate and filtered. The filtrate
was evaporated to leave a brown oil, which was dissolved in toluene
and washed with potassium hydroxide solution (5%, 150 ml) and
brine. Drying over magnesium sulphate and evaporation of the
solvent gave a yellow solid. Purification using an 800 g Biotage
column gave ethyl 1,4-diethoxy-2,3-naphthalenedicarboxylate as a
white solid (32 g, 90%).
[0219] .delta.H CDCl.sub.3 8.16, (2H, m), 7.60, (2H, m), 4.40, (4H,
q), 4.18, (4H, q), 1.50, (6H, t), 1.40, (6H, t).
Intermediate 3
1,4-Diethoxy-2,3-naphthalenedicarboxylic acid
[0220] Ethyl 1,4-diethoxy-2,3-naphthalenedicarboxylate (32 g, 89
mmol) was added to a solution of sodium hydroxide (20 g) in ethanol
(200 ml) and water (40 ml) and stirred for 1.5 h at 60.degree. C.
The reaction was cooled and the thick white suspension was
filtered. The solid was dissolved in a mixture of ethyl acetate
(200 ml) and water (800 ml). The layers were separated and the
aqueous was acidified with hydrochloric acid (2M, 120 ml). The
aqueous was extracted with ethyl acetate (2.times.) and the
combined organics were dried (MgSO.sub.4). Evaporation of the
solvent under vacuum gave 1,4-diethoxy-2,3-naphthalenedicarboxylic
acid as a white solid (25 g, 92%).
[0221] .delta.H [.sup.2H.sub.6]-DMSO 13.26, (2H, s), 8.15, (2H, m),
7.72, (2H, m), 4.13, (4H, q), 1.42, (6H, t).
Intermediate 4
1,4-Diethoxy-2,3-naphthalenedicarboxylic anhydride
[0222] 1,4-Diethoxy-2,3-naphthalenedicarboxylic acid (25 g, 82
mmol) was added to a solution of thionyl chloride (23.3 g) in
chloroform (150 ml) and stirred at reflux for 1 h. The resulting
solution was cooled and evaporated to dryness. Further chloroform
was added and evaporation repeated to give
1,4-diethoxy-2,3-naphthalenedicarboxylic anhydride as a yellow
solid (23.3 g, 99%).
[0223] .delta.H [.sup.2H.sub.6]-DMSO 8.42, (2H, m), 7.93, (2H, m),
4.53, (4H, q), 1.46, (6H, t).
Intermediate 5
Ethyl[4-(4,9-diethoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)pheny-
l]acetate
[0224] 1,4-Diethoxy-2,3-naphthalenedicarboxylic anhydride ( 23.3 g,
81.5 mmol) and ethyl (4-aminophenyl)acetate (14.8 g, 82 mmol) were
refluxed under nitrogen in acetic acid (160 ml) overnight. The
mixture was cooled to room temperature and poured into water (1 L).
The white solid was filtered, washed with water and dissolved in
dichloromethane (800 ml). The solution was washed with water, brine
and dried (MgSO.sub.4) and the solvent evaporated under vacuum to
give ethyl
[4-(4,9-diethoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etate as an off-white solid, 33 g, 96%.
[0225] .delta.H [.sup.2H.sub.6]-DMSO 8.40, (2H, m), 7.87, (2H, m),
7.42, (4H, s), 4.47, (4H, q), 4.12, (2H, q), 3.76, (2H, s), 1.45,
(6H, t), 1.21, (3H, t).
Intermediate 6
3-Hydroxy-4-methoxynaphtho[2,3-c]furan-1(3H)-one
[0226] N,N,N'-Trimethylethylene diamine (0.82 ml, 6.3 mmol) was
dissolved in tetrahydrofuran (16 ml) and cooled to -20.degree. C.
n-Butyl lithium (1.6M in hexanes, 3.9 ml, 6.24 mmol) was added and
the reaction stirred at -20.degree. C. for 15 min.
1-Methoxy-2-naphthaldehyde (0.96 g, 5.9 mmol) was added followed by
n-butyl lithium (1.6M in hexanes, 11.25 ml, 18 mmol) and the
reaction stirred at 25.degree. C. for 3 h. Solid carbon dioxide was
added and the reaction left until the excess carbon dioxide had
sublimed. Stirring continued for 15 min before addition of
hydrochloric acid (2N, 50 ml). The mixture was extracted with
dichloromethane (50 ml, .times.3). The combined extracts were dried
(MgSO.sub.4) and the solvent evaporated under vacuum. The oily
residue was preabsorbed onto silica and purified by SPE (silica, 10
g) eluting with an ethyl acetate/cyclohexane gradient to give
3-hydroxy-4-methoxynaphtho[2,3-c]furan-1(3H-one (50 mg, 3.7%).
[0227] .delta.H [.sup.2H.sub.6]-DMSO 8.28, (2H, m), 8.18, (2H, m),
7.70, (2H, m), 7.16, (1H, s), 4.27, (3H, s).
Intermediate 7
Ethyl 1,4-dimethoxy-2-methylnaphthalene-3-carboxylate
[0228] n-Butyl lithium (1.6M in hexanes, 4.1 ml, 6.56 mmol) was
added dropwise to 2-bromo-1,4-dimethoxy-3-methylnaphthalene (1.537
g, 5.47 mmol) in tetrahydrofuran (30 ml) at -50.degree. C. The
reaction was stirred for 30 min at -50.degree. C. before dropwise
addition of ethyl chloroformate (1 ml, 10.46 mmol). The reaction
was allowed to warm to 0.degree. C. over 18 h quenched by addition
of hydrochloric acid (2N) and extracted with ethyl acetate. The
extract was dried (Na.sub.2SO.sub.4) and the solvent evaporated
under vacuum. The residue was purified by SPE (silica, 10 g)
eluting with 10% ethyl acetate in cyclohexane to give ethyl
1,4-dimethoxy-2-methylnaphthalene-3-carboxylate (1.33 g, 89%).
[0229] .delta.H CDCl.sub.3 8.08, (2H, d), 7.53, (2H, m), 4.48, (2H,
q), 3.99, (3H, s), 3.88, (3H, s), 2.38, (3H, s), 1.44, (3H, t).
Intermediate 8
2,3-Bis(bromomethyl)-1,4-diethoxy-naphthalene
[0230] [1,4-Diethoxy-3-(hydroxymethyl)-2-naphthyl]methanol (92 mg,
0.33 mmol) was dissolved in a mixture of diethyl ether (1.5 ml) and
tetrahydrofuran (2 ml) under nitrogen at 0.degree. C. and
phosphorus tribromide (0.035 ml, 0.35 mmol) was added dropwise. The
reaction was allowed to warm to ambient temperature and stirred for
4 h before quenching with ice. The reaction mixture was extracted
with ethyl acetate (3.times.5 ml) and the combined organic extracts
dried over magnesium sulphate. The solvent was removed in vacuo,
and the residue purified by SPE cartridge (silica), gradient
elution cyclohexane to 75% cyclohexane/dichloromethane, to give
2,3-bis(bromomethyl)-1,4-diethoxy-naphthalene as a white solid (92
mg, 70%).
[0231] .delta.H CDCl.sub.3 8.07 (2H, dd, J=6.5, 3.2), 7.54 (2H, dd,
J=6.5, 3.2), 5.02 (4H, s), 4.21 (4H, q, J=7.0), 1.60 (6H, t,
J=7.0); LC retention time 4.16 min.
EXAMPLE 1 (PROCESS C)
[4-(4,9-Dimethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid
[0232] To a solution of ethyl
1,4-dimethoxy-2-methylnaphthalene-3-carboxylate (73 mg, 0.266 mmol)
in carbon tetrachloride (1 ml) was added N-bromosuccinimide (47 mg,
0.266 mmol) and dibenzylperoxide (5 mg). The mixture was heated at
reflux under nitrogen for 45 min, illuminating with a 200 W lamp.
The reaction was cooled to room temperature, 4-aminophenyl acetic
acid (40 mg, 0.266 mmol), triethylamine (74.mu.l, 0.53 mmol) and
DMF (5 ml) added and the reaction stirred for 48 h. Acetic acid
(glacial, 1 ml) was added to the reaction and the mixture refluxed
for 3h under nitrogen. Sodium metabisulphite solution (1 ml) was
added and the reaction evaporated to dryness under vacuum. The
product was partially purified by SPE (NH2, 10 g) eluting with
methanol then 5% acetic acid in methanol. The fractions containing
product were passed through a silica plug washing with 5% acetic
acid in methanol. After evaporation of the solvents under vacuum,
the residue was columned on a silica gel flash column eluting with
a gradient (1:1 ethyl acetate/cyclohexane to 5% methanol, 1% acetic
acid in 1:1 ethyl acetate/cyclohexane ) to give
[4-(4,9-dimethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceti-
c acid (15 mg, 15%).
[0233] .delta.H CDCl.sub.3 8.40, (1H, d), 8.17, (1H, d), 7.90. (2H,
d), 7.65, (1H, t), 7.59, (1H, t), 7.38, (2H, d), 5.02, (2H, s),
4.27, (3H, s), 4.08, (3H, s), 3.69, (2H, s). MS 378, [MH.sup.+]. LC
retention time 3.28 min.
EXAMPLE 2--STEP 1 (PROCESS E)
Ethyl[4-(4,9-diethoxy-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetate
[0234] A solution of 2,3-bis(bromomethyl)-1,4-diethoxy-naphthalene
(41 mg, 0.1 mmol) and 4-aminophenylacetic acid ethyl ester (20 mg,
0.11 mmol) in N,N-dimethylformamide (1 ml) was heated at 60.degree.
C. under nitrogen for 14 h. The solvent was removed in vacuo and
the residue taken up in ethyl acetate (10 ml) and washed with 8%
aqueous sodium bicarbonate solution (5 ml). The organic layer was
dried over magnesium sulphate and the solvent removed in vacuo.
Purification by flash column chromatography on silica gel eluting
with 90% cyclohexane/ethyl acetate gave the product as a white
solid (15 mg, 36%).
[0235] .delta.H CDCl.sub.3 8.12 (2H, dd, J=6.5, 3.2), 7.50 (2H, dd,
J=6.5, 3.2), 7.23 (2H, d, J=8.5), 6.73 (2H, d, J=8.5), 4.80 (4H,
s), 4.17 (6H, m), 3.55 (2H, s), 1.5 1.24 (3H, m); LC retention time
4.25 min, ms 420, [MH.sup.+].
EXAMPLE 2 --STEP 2
[4-(4,9-diethoxy-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid
[0236] A solution of
ethyl[4-(4,9-diethoxy-1,3-dihydro-2H-benzo[tisoindol-2-yl)phenyl]acetate
(10 mg, 0.024 mmol) in tetrahydrofuran (4 ml) and a solution of
lithium hydroxide (6 mg, 0.24 mmol) in water (1 ml) were stirred
vigorously for 14 h. The reaction mixture was diluted with water
(10 ml) and extracted with ethyl acetate (2.times.5 ml) and the
organic extracts discarded. The aqueous phase was acidified with 2N
hydrochloric acid to pH=5 and extracted with ethyl acetate
(3.times.5 ml). The combined organic extracts were dried over
magnesium sulphate and the solvent removed in vacuo to give the
product as a red solid (4 mg, 43%).
[0237] .delta.H CDCl.sub.3 8.13 (2H, dd, J=6.5,3.2), 7.49, (2H, dd,
J=6.5,3.2), 7.24 (2H, d, 8.3), 6.75 (2H, d, J=8.3), 4.81 (4H, s),
4.19 (4H, q, J=7.0), 3.69 (2H, s), 1.53 (6H, t, J=7.0); LC
retention time 3.92 min, ms 392, [MH.sup.+].
General Methodology
Method A
[0238] A mixture of ethyl
1,4-dihydroxy-2,3-naphthalenedicarboxylate (1.0 g, 3.29 mmol),
potassium carbonate (5 g, 36.2 mmol) and the alkyl halide (3.25
mmol) in acetone (20 ml) was heated at reflux under nitrogen for 8
h. The cooled reaction was filtered and the residue washed with
acetone and ethyl acetate. The combined filtrate and washings were
evaporated to dryness under vacuum. The residue was partitioned
between hydrochloric acid (2N) and dichloromethane. The
dichloromethane extract was evaporated to dryness under vacuum. The
product was isolated by chromatography on a silica gel flash column
eluting with an ethyl acetate/cyclohexane gradient (0-10% ethyl
acetate).
Method B
[0239] A mixture of monoalkylated material (170 mg, 0.49 mmol),
potassium carbonate (850 mg, 6.15 mmol) and the alkyl halide
(1.Ommol) in acetone (5 ml) was heated at reflux under nitrogen for
4 h. The cooled reaction was filtered and the residue washed with
acetone and ethyl acetate. The combined filtrate and washings were
evaporated to dryness under vacuum and the residue purified by SPE
(silica) eluting with an ethyl acetate/cyclohexane gradient.
[0240] Method C A mixture of ethyl
1,4-dihydroxy-2,3-naphthalenedicarboxylate (2 g, 6.57 mmol),
potassium carbonate (10 g, 72.4 mmol) and the alkyl halide
(64.lmmol) in acetone (40 ml) was heated at reflux under nitrogen
for 4 h. The cooled reaction was filtered and the residue washed
with acetone and ethyl acetate. The combined filtrate and washings
were evaporated to dryness under vacuum and the residue purified by
SPE (silica) eluting with an ethyl acetate/cyclohexane
gradient.
Method D
[0241] A mixture of the diester (13.87 mmol) and sodium hydroxide
solution (2N, 25 ml) in ethanol (25 ml) was heated at reflux for 4
h. The resulting solution was acidified to pH1 with hydrochloric
acid (2N) and extracted with ethyl acetate (.times.2). The extracts
were dried (MgSO.sub.4) and the solvent evaporated under
vacuum.
Method E (Process A)
[0242] A mixture of diacid (0.57 mmol) and 4-aminophenylacetic acid
(1.32 mmol) in glacial acetic acid (5 ml) was heated under reflux
for 24 h. The cooled reaction was diluted with water, the
precipitate formed filtered off and washed with water.
Method F
[0243] A mixture of diacid (0.56 mmol) and ethyl
4-aminophenylacetate (1.11 mmol) in glacial acetic acid (5 ml) was
heated at reflux for 24 h. The cooled reaction was diluted with
water, the precipitate formed filtered off and washed with
water.
Method G (Process B--Step 1)
[0244] The phthalimide ester (0.32 mmol) was dissolved in glacial
acetic acid (4 ml) and zinc powder (100 mesh, 300 mg, 4.59 mmol)
added. The reaction was heated at reflux under nitrogen for 72 h.
The hot reaction was filtered and the residue washed with hot
acetic acid. The combined filtrate and washings were evaporated to
dryness under vacuum. Methylamine (33% in ethanol, 2 ml) was added
to the resulting solid and the suspension was stirred at room
temperature for 20 min. The methylamine solution was evaporated
under vacuum and the residue purified by SPE (silica) eluting with
an ethyl acetate/cyclohexane gradient to give a mixture of isomeric
.gamma.-lactams.
Method H (Processes B and D--Step 2)
[0245] The .gamma.-lactams (0.06 mmol) were mixed with potassium
carbonate (1.09 mmol) in ethanol (2 ml) and water (1 ml) and heated
at reflux for 4 h. The cooled solution was acidified to pH1 with
hydrochloric acid (2M), the precipitate filtered off and washed
with water. Dried at 40.degree. C. under vacuum.
[0246] The following compounds were prepared using the above
general methodologies:
Intermediate 9
Ethyl
[4-(4,9-di-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl-
)phenyl]acetate
[0247] Ethyl
[4-(4,9-di-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetate was prepared in 49% yield from
1,4-di-isopropoxynaphthalene-2,3-dicarboxylic acid using method
F.
[0248] .delta.H [.sup.2H.sub.6]-DMSO 8.41, (2H, m), 7.83, (2H, m),
7.42, (4H, s), 5.02, (2H, m), 4.12, (2H, q), 3.76, (2H, s), 1.36,
(12H, d), 1.22, (3H, t).
Intermediate 10
Ethyl
[4-(4,9-dipropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetate
[0249] Ethyl
[4-(4,9-dipropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]a-
cetate was prepared in 68% yield from
1,4-dipropoxynaphthalene-2,3-dicarboxylic acid using method F.
[0250] .delta.H [.sup.2H.sub.6]-DMSO 8.35, (2H, m), 7.82, (2H, m),
7.37, (4H, s), 4.34, (4H, t), q), 3.71, (2H, s), 1.83, (4H, m),
1.17, (3H, t), 1.01, (6H, t).
Intermediate 11
Ethyl
[4-(4,9-dibutoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetate
[0251] Ethyl
[4-(4,9-dibutoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etate was prepared in 39% yield from
1,4-dibutoxynaphthalene-2,3-dicarboxylic acid using method F.
[0252] .delta.H [ H6]-DMSO 8.39, (2H, m), 7.87, (2H, m), 7.42, (4H,
s), 4.43, (4H, t), 4.12 , (2H, q), 3.76, (2H, s), 1.85, (4H, m),
1.53, (4H, m), 1.22, (3H, t), 0.97, (6H, t).
Intermediate 12
Ethyl
[4-(4,9-dihexyloxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetate
[0253] Ethyl
[4-(4,9-dihexyloxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-
acetate was prepared from
1,4-dihexyloxynaphthalene-2,3-dicarboxylic acid using method F.
[0254] .delta.H [.sup.2H.sub.6]-DMSO 8.38, (2H, m), 7.86, (2H, m),
7.42, (4H, s), 4.41, (4H, t), 4.12, (2H, q), 3.76, (2H, s), 1.85,
(4H, m), 1.49, (4H, m), 1.32, (8H, m), 1.21, (3H, t), 0.87, (6H,
t).
Intermediate 13
Ethyl
[4-(4-ethoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol--
2-yl)phenyl]acetate
[0255] Ethyl
[4-(4-ethoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-
phenyl]acetate was prepared from
1-ethoxy4-isopropoxynaphthalene-2,3-dicarboxylic acid using method
F.
[0256] .delta.H [2H.sub.6]-DMSO 8.36, (2H, m), 7.79, (2H, m), 7.37,
(4H, s), 4.98, (1H, m), 4.42, (2H, q), 4.07, (2H, q), 3.71, (2H,
s), 1.40, (3H, t), 1.31, (6H, d), 1.17, (3H, t).
Intermediate 14
Ethyl
[4-(9-isopropoxy-4-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-
-2-yl)phenyl]acetate
[0257] Ethyl
[4-(9-isopropoxy-4-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl-
)phenyl]acetate was prepared from
4-isopropoxy-1-propoxynaphthalene-2,3-dicarboxylic acid using
method F.
[0258] .delta.H [.sup.2H.sub.6]-DMSO 8.35, (2H, m), 7.80, (2H, m),
7.37, (4H, s), 4.97, (1H, m), 4.34, (2H, t), 4.07, (2H, q), 3.71,
(2H, s), 1.83, (2H, m), 1.31, (6H, d), 1.71, (3H, t), 1.01, (3H,
t).
Intermediate 15
Ethyl
[4-(4-hexyloxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindo-
l-2-yl)phenyl]acetate
[0259] Ethyl
[4-(4-hexyloxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-y-
l)phenyl]acetate was prepared from
1-hexyloxy-4-isopropoxynaphthalene-2,3-dicarboxylic acid using
method F.
[0260] .delta.H [.sup.2H.sub.6]-DMSO 8.37, (1H, m), 8.32, (1H, m),
7.80, (2H, m), 7.37, (4H, s), 4.97, (1H, m), 4.37, (2H, t), 4.07,
(2H, q), 3.71, (2H, s), 1.81, (2H, m), 1.45, (2H, m), 1.35-1.26,
(10H, m), 1.17, (3H, t), 0.82, (3H, t).
Intermediate 16
1,4-Di-isopropoxynaphthalene-2,3-dicarboxylic acid
[0261] 1,4-Di-isopropoxynaphthalene-2,3-dicarboxylic acid was
prepared from ethyl 1,4-di-propoxynaphthalene-2,3-dicarboxylate
using method D.
[0262] .delta.H [.sup.2H.sub.6]-DMSO 8.16, (2H, m), 7.67, (2H, m),
4.43, (2H, m), 1.26, (12H, d).
Intermediate 17
1,4-Dipropoxynaphthalene-2,3-dicarboxylic acid
[0263] 1,4-Dipropoxynaphthalene-2,3-dicarboxylic acid was prepared
from ethyl 1,4-dipropoxynaphthalene-2,3-dicarboxylate using method
D.
[0264] .delta.H [.sup.2H.sub.6]-DMSO 8.14, (2H, m), 7.71, (2H, m),
4.01, (4H, t), 1.83, (4H, m), 1.05, (6H, t).
Intermediate 18
1,4-Dibutoxynaphthalene-2,3-dicarboxylic acid
[0265] 1,4-Dibutoxynaphthalene-2,3-dicarboxylic acid was prepared
from ethyl 1,4-dibutoxynaphthalene-2,3-dicarboxylate using method
D.
[0266] .delta.H [.sup.2H.sub.6]-DMSO 8.12, (2H, m), 7.12, (2H, m),
4.05, (4H, t), 1.80, (4H, m), 1.52, (4H, m), 0.97, (6H, t).
Intermediate 19
1,4-Dihexyloxynaphthalene-2,3-dicarboxylic acid
[0267] 1,4-Dihexyloxynaphthalene-2,3-dicarboxylic acid was prepared
from ethyl 1,4-dihexyloxynaphthalene-2,3-dicarboxylate using method
D.
[0268] .delta.H [.sup.2H.sub.6]-DMSO 8.39, (2H, m), 7.92, (2H, m),
4.46, (4H, t), 1.85, (4H, m), 1.49, (4H, m), 1.32, (8H, m), 0.88,
(6H, t).
Intermediate 20
1-Ethoxy-4-isopropoxynaphthalene-2,3-dicarboxylic acid
[0269] 1-Ethoxy-4-isopropoxynaphthalene-2,3-dicarboxylic acid was
prepared from ethyl
1-ethoxy-4-isopropoxynaphthalene-2,3-dicarboxylate using method
D.
[0270] .delta.H [.sup.2H.sub.6]-DMSO 8.18, (1H, m), 8.12, (1H, m),
7.69, (2H, m), 4.40, (1H, m), 4.11, (2H, q), 1.41, (3H, t), 1.27,
(6H, d).
Intermediate 21
4-Isopropoxy-1-propoxynaphthalene-2,3dicarboxylic acid
[0271] 4-Isopropoxy-1-propoxynaphthalene-2,3-dicarboxylic acid was
prepared from ethyl
4-isopropoxy-1-propoxynaphthalene-2,3-dicarboxylate using method
D.
[0272] .delta.H [.sup.2H.sub.6]-DMSO 8.18, (1H, m), 8.11, (1H, m),
7.70, (2H, m), 4.41, (1H, m), 4.02, (2H, t), 1.83, (2H, m), 1.27,
(6H, d), 1.06, (3H, t).
Intermediate 22
1-Butoxy-4-isopropoxynaphthalene-2,3-dicarboxylic acid
[0273] 1-Butoxy-4-isopropoxynaphthalene-2,3-dicarboxylic acid was
prepared from ethyl
1-butoxy-4-isopropoxynaphthalene-2,3-dicarboxylate using method
D.
[0274] .delta.H [.sup.2H.sub.6]-DMSO 8.18, (1H, m), 8.09, (1H, m),
7.69, (2H, m), 4.40, (1H, m), 4.05, (2H, t), 1.80, (2H, m), 1.52,
(2H, m), 1.26, (6H, d), 0,97, (3H, t).
Intermediate 23
1-Hexyloxy-4-isopropoxynaphthalene-2,3-dicarboxylic acid
[0275] 1-Hexyloxy4-isopropoxynaphthalene-2,3-dicarboxylic acid was
prepared from ethyl
1-hexyloxy-4-isopropoxynaphthalene-2,3-dicarboxylate using method
D.
[0276] .delta.H [.sup.2H.sub.6]-DMSO 8.18, (1H, m), 8.09, (1H, m),
7.70, (2H, m), 4.40, (1H, m), 4.04, (2H, t), 1.81, (2H, m), 1.49,
(2H, m), 1.34, (4H, m), 1.27, (6H, d), 0.90, (3H, t).
Intermediate 24
Ethyl 1,4-di-isopropoxynaphthalene-2,3-dicarboxylate
[0277] Ethyl 1,4-di-isopropoxynaphthalene-2,3-dicarboxylate was
prepared from ethyl 1,4-dihydroxynaphthalene-2,3-dicarboxylate and
2-iodopropane using method C.
[0278] .delta.H [.sup.2H.sub.6]-DMSO 8.18, (2H, m), 7.73, (2H, m),
4.37, (2H, m), 4.28, (4H, q), 1.30, (6H, t), 1.25, (12H, d).
Intermediate 25
Ethyl 1,4-dipropoxynaphthalene-2,3-dicarboxylate
[0279] Ethyl 1,4-dipropoxynaphthalene-2,3-dicarboxylate was
prepared from ethyl 1,4-dihydroxynaphthalene-2,3-dicarboxylate and
1-iodopropane using method C.
[0280] .delta.H [.sup.2H.sub.6]-DMSO 8.16, (2H, m), 7.77, (2H, m),
4.29, (4H, q), 4.00, (4H, t), 1.83 , (4H, m), 1.30,(4H, t),
1.04,(4H, t).
Intermediate 26
Ethyl 1,4-dibutoxynaphthalene-2,3-dicarboxylate
[0281] Ethyl 1,4-dibutoxynaphthalene-2,3-dicarboxylate was prepared
from ethyl 1,4-dihydroxynaphthalene-2,3-dicarboxylate and
1-iodobutane using method C.
[0282] .delta.H [.sup.2H.sub.6]-DMSO 8.15, (2H, m), 7.76, (2H, m),
4.29, (4H, q), 4.03, (4H, t), 1.79 , (4H, m), 1.50, (4H, m), 1.30,
(6H, t), 0.96, (6H, t).
Intermediate 27
Ethyl 1,4-dihexyloxynaphthalene-2,3-dicarboxylate
[0283] Ethyl 1,4-dihexyloxynaphthalene-2,3-dicarboxylate was
prepared from ethyl 1,4-dihydroxynaphthalene-2,3-dicarboxylate and
2-iodohexane using method C.
[0284] .delta.H [.sup.2H.sub.6]-DMSO 8.14, (2H, m), 7.76, (2H, m),
4.29, (4H, q), 4.03, (4H, t), 1.81, (4H, m), 1.47, (4H, m),
1.38-1.21, (14H, m), 0.88, (6H, t).
Intermediate 28
Ethyl 1-ethoxy4-isopropoxynaphthalene-2,3-dicarboxylate
[0285] Ethyl 1-ethoxy-4-isopropoxynaphthalene-2,3-dicarboxylate was
prepared in 91% yield from ethyl
1-hydroxy-4-isopropoxynaphthalene-2,3-dicarboxylate and iodoethane
using method B.
[0286] .delta.H CDCl.sub.3 8.22, (1H, m), 8.13, (1H, m), 7.59, (2H,
m), 4.40, (5H, m), 4.18, (2H, q), 1.49, (3H, t), 1.43-1.38, (6H,
m),1.34, (6H, d).
Intermediate 29
Ethyl 4-isopropoxy-1-propoxynaphthalene-2,3-dicarboxylate
[0287] Ethyl 4-isopropoxy-1-propoxynaphthalene-2,3-dicarboxylate
was prepared in 91% yield from ethyl
1-hydroxy-4-isopropoxynaphthalene-2,3-dicarboxylate and
1-iodopropane using method B.
[0288] .delta.H CDCl.sub.3 8.22, (1H, m), 8.14, (1H, m), 7.60, (2H,
m), 4.40, (5H, m), 4.07, (2H, t), 1.92, (2H, m), 1.40, (6H, m),
1.34, (6H, d), 1.10, (3H, t).
Intermediate 30
Ethyl 1-butoxy-4-isopropoxynaphthalene-2,3-dicarboxylate
[0289] Ethyl 1-butoxy4-isopropoxynaphthalene-2,3-dicarboxylate was
prepared from ethyl
1-hydroxy4-isopropoxynaphthalene-2,3-dicarboxylate and 1-iodobutane
using method B.
[0290] .delta.H [.sup.2H.sub.6]-DMSO 8.20, (1H, m), 8.12, (1H, m),
7.75, (2H, m), 4.38 -4.25, (5H, m), 4.04, (2H, t), 1.80, (2H, m),
1.50, (2H, m), 1.30, (6H, t), 1.25, (6H, d), 0.96, (3H, t).
Intermediate 31
Ethyl 1-hexyloxy-4-isopropoxynaphthalene-2,3-dicarboxylate
[0291] Ethyl 1-hexyloxy-4-isopropoxynaphthalene-2,3-dicarboxylate
was prepared in 80 yield from ethyl
1-hydroxy-4-isopropoxynaphthalene-2,3-dicarboxylate and
1-iodohexane using method B.
[0292] .delta.H CDCl.sub.3 8.21, (1H, m), 8.13, (1H, m), 7.59, (2H,
m), 4.40, (5H, m), 4.10, (2H, t), 1.90, (2H, m), 1.53, (2H, m),
1.45-1.31, (16H, m), 0.92, (3H, t).
Intermediate 32
Ethyl 1-ethoxy4-hydroxynaphthalene-2,3-dicarboxylate
[0293] Ethyl 1-ethoxy-4-hydroxynaphthalene-2,3-dicarboxylate was
prepared from ethyl 1,4-dihydroxynaphthalene-2,3-dicarboxylate and
iodoethane using method A.
[0294] .delta.H [.sup.2H.sub.6]-DMSO 8.36, (1H, d), 8.06, (1H, d),
7.83, (1H, m), 7.72, (1H, m), 4.35, (4H, m), 4.03, (2H, q), 1.39,
(3H, t), 1.32, (6H, m).
Intermediate 33
Ethyl 1-hydroxy-4-isopropoxynaphthalene-2,3-dicarboxylate
[0295] Ethyl 1-hydroxy-4-isopropoxynaphthalene-2,3-dicarboxylate
was prepared in 36% yield from ethyl
1,4-dihydroxynaphthalene-2,3-dicarboxylate and 2-iodopropane using
method A.
[0296] .delta.H CDCl.sub.3 12.3, (1H, s), 8.45, (1H, d), 8.10, (1H,
d), 7.65, (1H, m), 7.55, (1H, m), 4.42, (1H, m), 1.41, (6H, t),
1.32, (6H, d).
EXAMPLE 4--STEP 1 (PROCESS B)
Ethyl
[4-(4,9-di-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetate
[0297] Ethyl
[4-(4,9-di-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]a-
cetate was prepared in 16% yield from ethyl
[4-(4,9-di-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetate using method G.
[0298] .delta.H [.sup.2H.sub.6]-DMSO 8.34, (1H, d), 8.16, (1H, d),
7.93, (2H, d), 7.68, (1H, t), 7.60 , (1H, t), 7.34, (2H, d), 5.10,
(2H, s), 5.01, (1H, m), 4.68, (1H, m), 4.10, (2H, q), 3.69, (2H,
s), 1.40, (3H, d), 1.35, (3H, d), 1.19, (3H, t).
EXAMPLE 4--STEP 2
[4-(4,9-Di-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etic acid
[0299]
[4-(4,9-Di-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)p-
henyl]acetic acid was prepared in 81% yield from ethyl
[4-(4,9-di-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]a-
cetate using method H.
[0300] .delta.H [.sup.2H.sub.6]-DMSO 8.34, (1H, d), 8.17, (1 H, d),
7.91, (2H, d), 7.69, (1H, m), 7.61, (1H, m), 7.34, (2H, d), 5.10,
(2H, s), 5.02, (1H, m), 4.68, (1H, m), 3.59, (2H, s), 1.38, (6H,
d), 1.34, (6H, d). MS 434, [MH.sup.+]. LC retention time 3.91
min.
EXAMPLE 5--STEP 1 (PROCESS B)
Ethyl
[4-(4,9-dipropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-
acetate
[0301] Ethyl
[4-(4,9-dipropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceta-
te was prepared in 13% yield from ethyl
[4-(4,9-dipropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]a-
cetate using method G.
[0302] .delta.H [.sup.2H.sub.6]-DMSO 8.32, (1H, d), 8.19, (1H, d),
7.93, (2H, d), 7.72, (1H, t), 7.65, (1H, t), 7.36, (2H, d), 5.19,
(2H, s), 4.30, (2H, t), 4.22, (2H, t), 4.10, (2H, q), 3.69, (2H,
s), 1.87, (4H, m), 1.20, (3H, t), 1.13-1.05, (6H, m).
EXAMPLE 5--STEP 2
[4-(4,9-Dipropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid
[0303]
[4-(4,9-Dipropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)pheny-
l]acetic acid was prepared in 89% yield from ethyl
[4-(4,9-dipropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceta-
te using method H.
[0304] .delta.H [.sup.2H.sub.6]-DMSO 8.32, (1H, d), 8.19, (1H, d),
7.91, (2H, d), 7.71, (1H, t), 7.65, (1H, t), 7.65, (2H, d), 5.19,
(2H, s), 4.30, (2H, t), 4.22, (2H, t), 3.59, (2H, s), 1.89, (4H,
m), 1.09, (6H, m). MS 434, [MH.sup.+]. LC retention time 3.97
min.
EXAMPLE 6--STEP 1 (PROCESS B)
Ethyl
[4-(4,9-dibutoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]a-
cetate
[0305] Ethyl
[4-(4,9-dibutoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetat-
e was prepared in 26% yield from ethyl
[4-(4,9-dibutoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etate using method G.
[0306] .delta.H [.sup.2H.sub.6]-DMSO 8.22, (1H, d), 8.09, (1H, d),
7.84, (2H, d), 7.63, (1H, t), 7.57, (1H, t), 7.27, (2H, d), 5.10,
(2H, s), 4.26, (2H, t), 4.17, (2H, t), 4.02, (2H, q), 3.60, (2H,
s), 1.77, (4H, quintet), 1.49, (4H, m), 1.12, (3H, t), 0.91, (6H,
q).
EXAMPLE 6--STEP 2
[4-(4,9-Dibutoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid
[0307]
[4-(4,9-Dibutoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl-
]acetic acid was prepared in 98% yield from ethyl
[4-(4,9-dibutoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetat-
e using method H.
[0308] .delta.H [.sup.2H.sub.6]-DMSO 8.30, (1H, d), 8.18, (1H, d),
7.91, (2H, d), 7.71, (1 H, t), 7.65, (1H, t), 7.35, (2H, d), 5.19,
(2H, s), 4.34, (2H, t), 4.26, (2H, t), 3.59, (2H, s), 1.85, (4H,
m), 1.57, (4H, m), 0.99, (6H, m). MS 462, [MH.sup.+]. LC retention
time 4.25 min.
EXAMPLE 7--STEP 1 (PRECESS B)
Ethyl
[4-(4,9-dihexyloxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl-
]acetate
[0309] Ethyl
[4-(4,9-dihexyloxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acet-
ate was prepared in 28% yield from ethyl
[4-(4,9-dihexyloxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]-
acetate using method G.
[0310] .delta.H [.sup.2H.sub.6]-DMSO 8.19, (1H, d), 8.07, (1H, d),
7.82, (2H, d), 7.60, (1H, t), 7.54, (1H, t), 7.25, (2H, d), 5.08,
(2H, s), 4.23, (2H, t), 4.15, (2H, t), 3.99, (2H, q), 3.58, (2H,
s), 1.75, (4H, quintet), 1.50-1.36, (4H, m), 1.29-1.21, (8H, m),
1.09, (3H, t), 0.79, (6H, q).
EXAMPLE 7--STEP 2
[4-(4,9-Dihexyloxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]aceti-
c acid
[0311]
[4-(4,9-Dihexyloxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetic acid was prepared in 97% yield from ethyl
[4-(4,9-dihexyloxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acet-
ate using method H.
[0312] .delta.H [.sup.2H.sub.6]-DMSO 8.30, (1H, d), 8.17, (1H, d),
7.91, (2H, d), 7.71, (1H, t), 7.64 (1H, t), 7.34, (2H, d), 5.18,
(2H, s), 4.33, (2H, t), 4.25, (2H, t), 3.59, (2H, s), 1.86, (4H,
m), 1.54, (4H, m), 1.35, (8H, m), 0.90, (6H, m). MS 518,
[MH.sup.+]. LC retention time 4.76 min.
EXAMPLE 8- STEP 1 (PROCESS B)
Ethyl
[4-(4-ethoxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl-
)phenyl]acetate and ethyl
[4-(9-ethoxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetate
[0313] A mixture of ethyl
[4-(4-ethoxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetate and ethyl
[4-(9-ethoxy4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)pheny-
l]acetate (60:40) was prepared in 20% yield from ethyl
[4-(4-ethoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-
phenyl]acetate using method G.
[0314] .delta.H [.sup.2H.sub.6]-DMSO 8.25, (1H, m), 8.09, (1H, m),
7.85, (2H, d), 7.64-7.58, (2H, m), 7.26, (2H, d), 5.09, (1.2H, s),
5.02, (0.8H, s), 4.90, (0.6H, m), 4.60, (0.4H, m), 4.32, (0.8H, q),
4.22, (1.2H, q), 4.01, (2H, q), 3.60, (2H, s), 1.38, (3H, m), 1.29,
(2.4H, d), 1.24, (3.6H, d), 1.11, (3H, t).
EXAMPLE 8--STEP 2
[4-(4-Ethoxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)pheny-
l]acetic acid and
[4-(9-ethoxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetic acid
[0315] A mixture of
[4-(4-ethoxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetic acid and
[4-(9-ethoxy4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)pheny-
l]acetic acid (60:40) was prepared in 98% yield from ethyl
[4-(4-ethoxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetate and ethyl
[4-(9-ethoxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetate (60:40) using method H.
[0316] .delta.H [2H.sub.6]-DMSO 8.34, (1H, m), 8.18, (1H, m), 7.92,
(2H, d), 7.70, (1H, t), 7.68, (1H, t), 7.34, (2H, d), 5.18, (1.2H,
s), 5.11, (0.8H, s), 5.01, (0.6H, m), 4.69, (0.4H, m), 4.40, (0.8H,
q), 4.31, (1.2H, q), 3.59, (2H, s), 1.46, (3H, m), 1.37, (2.4H, d),
1.33, (3.6H, d). MS 420, [MH.sup.+]. LC retention time 3.73
min.
EXAMPLE 9--STEP 1 (PROCESS B)
Ethyl
[4-(9-isopropoxy-4-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-y-
l)phenyl]acetate and ethyl
[4-(4-isopropoxy-9-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetate
[0317] A mixture of ethyl
[4-(9-isopropoxy4-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetate and ethyl
[4-(4-isopropoxy-9-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetate (60:40) was prepared in 21% yield from ethyl
[4-(9-isopropoxy-4-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl-
)phenyl]acetate using method G.
[0318] .delta.H [.sup.2H.sub.6]-DMSO 8.25, (1H, m), 8.10, (1H, m),
7.85, (2H, m), 7.62, (1H, m), 7.53, (1H, m), 7.27, (2H, d), 5.10,
(1.2H, s), 5.02, (0.8H, s), 4.91, (0.6H, m), 4.58, (0.4H, m), 4.23,
(0.8H, t), 4.13, (1.2H, t), 4.01, (2H, q), 3.60, (2H, s), 1.80,
(2H, m), 1.29, (2.4H, d), 1.24, (3.6H, d), 1.1 1, (3H, t), 1.01,
(3H, m).
EXAMPLE 9--STEP 2
[4-(9-isopropoxy-4-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetic acid and
[4-(4-isopropoxy-9-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetic acid
[0319] A mixture of
[4-(9-isopropoxy-4-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetic acid and
[4-(4-isopropoxy-9-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetic acid (60:40) was prepared in quantitative yield from
ethyl
[4-(9-isopropoxy4-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phen-
yl]acetate and ethyl
[4-(4-isopropoxy-9-propoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetate (60:40) using method H.
[0320] .delta.H [2H.sub.6]-DMSO 8.34, (1H, m), 8.18, (1H, m), 7.92,
(2H, m), 7.70. (1H, t), 7.63, (1H, m), 7.34, (2H, d), 5.18, (1.2H,
s), 5.11, (0.8H, s), 5.01, (0.6H, m), 4.68, (0.4H, m), 4.32, (0.8H,
q), 4.22, (1.2H, q), 3.59, (2H, s), 1.89, (2H, m), 1.37, (2.4H, d),
1.33, (3.6H, d), 1.10, (3H, m). MS 434, [MH.sup.+]. LC retention
time 3.89 min.
EXAMPLE 10--STEP 1 (PROCESS B)
Ethyl
[4-(4-hexyloxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2--
yl)phenyl]acetate and ethyl
[4-(9-hexyloxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetate
[0321] A mixture of ethyl
[4-(4-hexyloxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetate and ethyl
[4-(9-hexyloxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetate (60:40) was prepared in 16% yield from ethyl
[4-(4-hexyloxy-9-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)p-
henyl]acetate using method G.
[0322] .delta.H [.sup.2H.sub.6]-DMSO 8.33, (1H, m), 8.17, (1H, m),
7.94, (2H, m), 7.70, (1H, m), 7.64, (1H, m), 7.35, (2H, d), 5.18,
(1.2H, s), 5.11, (0.8H, s), 5.00, (0.6H, m), 4.69, (0.4H, m), 4.35,
(0.8H, t), 4.25, (1.2H, t), 4.10, (2H, q), 3.69, (2H, s), 1.87,
(2H, m), 1.60-1.45, (2H, m), 1.37, (2.4H, d), 1.33,(3.6H, d), 1.20,
(3H, t), 0.91, (3H, m).
EXAMPLE 10--STEP 2
[4-(4-Hexyloxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetic acid and
[4-(9-hexyloxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetic acid
[0323] A mixture of
[4-(4-hexyloxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetic acid and
[4-(9-hexyloxy4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phe-
nyl]acetic acid (60:40) was prepared in 78% yield from ethyl
[4-(4-hexyloxy-9-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetate and ethyl
[4-(9-hexyloxy-4-isopropoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetate (60:40) using method H.
[0324] .delta.H [.sup.2H.sub.6]-DMSO 8.35, (0.6H, d), 8.30, (0.4H,
d), 8.17, (2H, m), 7.91, (2H, m), 7.70, (1H, t), 7.63, (1H, m),
7.34, (2H, d), 5.18, (1.2H, s), 5.10, (0.8H, s), 5.00, (0.6H, m),
4.68, (0.4H, m), 4.35, (0.8H, q), 4.25, (1.2H, q), 3.59, (2H, s),
1.87, (2H, m), 1.54, (2H, m), 1.35, (10H, m), 0.91, (3H, m). MS
476, [MH.sup.+]. LC retention time 4.32 min.
EXAMPLE 11--STEP 1 (PROCESS D)
Ethyl
[4-(4-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acet-
ate
[0325] 3-Hydroxy4-methoxynaphtho[2,3-c]furan-1 (3H)-one (50 mg,
0.22 mmol) and ethyl 4-aminophenylacetate (47 mg, 0.26 mmol) in
dichloromethane (5 ml) were stirred at room temperature under
nitrogen for 1 hour. Sodium triacetoxyborohydride (138 mg, 0.66
mmol) was added and stirring continued for 24 h. The reaction was
adjusted to pH14 with sodium hydroxide solution (2N) and extracted
with dichloromethane (3.times.5 ml). The combined extracts were
evaporated under vacuum and the residue triturated with
cyclohexane/ether to give ethyl
[4-(4-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetate
as a white solid (45 mg, 54%).
[0326] .delta.H [.sup.2H.sub.6]-DMSO 8.24, (1H, d), 8.16, (1H, d),
8.13, (1H, s), 7.99, (2H, d), 7.64, (2H, m), 7.37, (2H, d), 5.44,
(2H, s), 4.26, (3H, s), 4.10, (2H, q), 3.69, (2H, s), 1.20, (3H,
t).
EXAMPLE 11--STEP 2
[4-(4-Methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetic
acid
[0327]
[4-(4-Methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etic acid was prepared in quantitative yield from ethyl
[4-(4-methoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetate
using method H.
[0328] .delta.H [2H.sub.6]-DMSO 8.19, (1H, d), 8.09, (2H, m), 7.92,
(2H, d), 7.59, (2H, m), 7.31, (2H, d), 5.39, (2H, s), 4.21, (3H,
s), 3.56, (2H, s). MS 348, [MH.sup.+]. LC retention time 3.50
min.
EXAMPLE 12
[4-(4,9-Diethoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ace-
tic acid
[0329]
[4-(4,9-Diethoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetic acid was prepared from
1,4-diethoxynaphthalene-2,3-dicarboxylic acid using method E.
[0330] .delta.H [2H.sub.6]-DMSO 8.35, (2H, m), 7.81, (2H, m), 7.36,
(4H, s), 4.43, (4H, q), 3.62, (2H, s), 1.40, (6H, t). MS 420,
[MH.sup.+]. LC retention time 3.58 min.
EXAMPLE 13
[4-(4,9-Di-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)pheny-
l]acetic acid
[0331]
[4-(4,9-Di-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2--
yl)phenyl]acetic acid was prepared from
1,4-di-isopropoxynaphthalene-2,3-dicarboxylic acid using method
E.
[0332] .delta.H [.sup.2H.sub.6]-DMSO 8.41, (2H, m), 7.83, (2H, m),
7.41, (4H, s), 5.02, (2H, m), 3.66, (2H, s), 1.36, (12H, d). MS
448, [MH.sup.+]. LC retention time 3.74 min.
EXAMPLE 14
[4-(4,9-Dipropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ac-
etic acid
[0333]
[4-(4,9-Dipropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)p-
henyl]acetic acid was prepared from
1,4-dipropoxynaphthalene-2,3-dicarboxylic acid using method E.
[0334] .delta.H [.sup.2H.sub.6]-DMSO 8.39, (2H, m), 7.87, (2H, m),
7.41, (4H, s), 4.39, (4H, t), 3.67, (2H, s), 1.87, (4H, m), 1.05,
(6H, t). ). MS 448, [MH.sup.+]. LC retention time 3.89 min.
EXAMPLE 15
[4-(4,9-Dibutoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]ace-
tic acid
[0335]
[4-(4,9-Dibutoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)ph-
enyl]acetic acid was prepared from
1,4-dibutoxynaphthalene-2,3-dicarboxylic acid using method E.
[0336] .delta.H [2H.sub.6]-DMSO 8.39, (2H, m), 7.88, (2H, m), 7.41,
(4H, s), 4.43, (4H, t), 3.67, (2H, s), 1.84, (4H, m), 1.52, (4H,
m), 0.96, (6H, t). MS 476, [MH.sup.+]. LC retention time 4.15
min.
EXAMPLE 16
[4-(4,9-Dihexyloxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]a-
cetic acid
[0337]
[4-(4,9-Dihexyloxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)-
phenyl]acetic acid was prepared from
1,4-dihexyloxynaphthalene-2,3-dicarboxylic acid using method E.
[0338] .delta.H [.sup.2H.sub.6]-DMSO 8.38, (2H, m), 7.86, (2H, m),
7.41, (4H, s), 4.42, (4H, t), 3.67, (2H, s), 1.85, (4H, m), 1.49,
(4H, m), 1.32, (8H, m), 0.87, (6H, t). ). MS 532, [MH.sup.+]. LC
retention time 4.62 min.
EXAMPLE 17
[4-(4-Ethoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)p-
henyl]acetic acid
[0339]
[4-(4-Ethoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindo-
l-2-yl)phenyl]acetic acid was prepared from
1-ethoxy-4-isopropoxynaphthalene-2,3-dicarboxylic acid using method
E.
[0340] .delta.H [2H.sub.6]-DMSO 8.41, (2H, m), 7.84, (2H, m), 7.41,
(4H, s), 5.03, (1H, m), 4.48, (2H, q), 3.67, (2H, s), 1.45, (3H,
t), 1.36, (6H, d). MS 434, [MH.sup.+]. LC retention time 3.66
min.
EXAMPLE 18
[4-(9-isopropoxy4-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)p-
henyl]acetic acid
[0341]
[4-(9-isopropoxy-4-propoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoind-
ol-2-yl)phenyl]acetic acid was prepared from
4-isopropoxy-1-propoxynaphthalene-2,3-dicarboxylic acid using
method E.
[0342] .delta.H [.sup.2H.sub.6]-DMSO 8.41, (2H, m), 7.84, (2H, m),
7.41, (4H, s), 5.02, (1H, m), 4.39, (2H, t), 3.66, (2H, s), 1.88,
(2H, m), 1.36, (6H, d), 1.05, (3H, t). MS 448, [MH.sup.+]. LC
retention time 3.81 min.
EXAMPLE 19
[4-(4-Butoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)p-
henyl]acetic acid
[0343]
[4-(4-Butoxy-9-isopropoxy-1,3-dioxo-1,3-dihydro-2H-benzo[f]isoindo-
l-2-yl)phenyl]acetic acid was prepared from
1-butoxy-4-isopropoxynaphthalene-2,3-dicarboxylic acid using method
E.
[0344] .delta.H [.sup.2H.sub.6]-DMSO 8.42, (1H, m), 8.37, (1H, m),
7.85, (2H, m), 7.41, (4H, s), 5.02, (1H, m), 4.43, (2H, t), 3.66,
(2H, s), 1.85, (2H, m), 1.53, (2H, m), 1.36, (6H, d), 0.97, (3H,
t). MS 461, [MH.sup.+]. LC retention time 3.94 min.
Biological data
[0345] The ability of the compounds of the invention to bind to EP4
receptors has been demonstrated in the Human EP.sub.4 Scintillation
Proximity Assay.
[0346] Quantification of radioligand binding by scintillation
proximity assay (SPA) is a long-established principle. Briefly, the
affinity of novel compounds for a receptor is assessed by the
specific competition between known quantities of radiolabelled
ligand and novel compound for that receptor. Increasing
concentrations of novel compound reduce the amount of radiolabel
that binds to the receptor. This gives rise to a diminishing
scintillation signal from SPA beads coated with membranes that bear
the receptor. The signal may be detected with a suitable
scintillation counter and the data generated may be analysed with
suitable curve-fitting software.
[0347] The human EP.sub.4 SPA assay (hereafter referred to as `the
assay`) utilises membranes prepared from Chinese Hamster Ovary (CHO
cells) infected with Semliki Forest Virus (SFV). Genetically
engineered SFV-1 viral particles containing the genetic sequence of
the human EP4 receptor were used to infect CHO cells resulting in
expression of the receptor protein in cellular membranes. Cells
washed free of media are homogenised in a pH-buffered medium
containing peptidase inhibitors. A suitable buffer is of the
following composition: 50 mM HEPES, 1 mM EDTA, 25 pg/ml bacitracin,
100 .mu.M leupeptin, 1 mM PMSF, 2 .mu.M Pepstatin A, pH adjusted to
7.4 with KOH. Following removal of cell debris by a low-speed
centrifugation, a pellet of membranes is prepared by a high-speed
(48000 g) centrifugation of the resulting supernatant. Membrane
suspensions such as that described may be stored at -80.degree. C.
until used.
[0348] For assay, membranes expressing human EP.sub.4 receptors are
diluted in a pH-buffered medium and mixed with SPA beads coated
with a suitable substance to facilitate the adhesion of membranes
to the beads. The concentrations of membrane protein and SPA beads
chosen should result in SPA binding signal of at least 300
corrected counts per minute (CCPM) when tritiated radioligand at a
concentration close to its K.sub.d (affinity value) is combined
with the mixture. Non-specific binding (nsb) may be determined by
competition between the radiolabelled ligand and a saturating
concentration of unlabelled ligand. In order to quantify the
affinity of novel EP4 receptor ligands, compounds are diluted in a
stepwise manner across the wells of a 96-well plate. Radioligand,
novel compound, and unlabelled ligand are then added to a 96-well
plate suitable for the measurement of SPA binding signals prior to
the addition of bead/membrane mixture to initiate the binding
reaction. Equilibrium may be achieved by incubation at room
temperature for 120 minutes prior to scintillation counting. The
data so generated may be analysed by means of a computerised
curve-fitting routine in order to quantify the concentration of
compound that displaces 50% of the specific radioligand binding
(IC50). The affinity (pK.sub.i) of the novel compound may be
calculated from the IC50 by application of the Cheng-Prusoff
correction. Suitable reagents and protocols are: reaction buffer
containing 50 mM HEPES, 10 mM MgCl.sub.2, pH adjusted to 7.4 with
KOH; SPA beads coated with wheatgerm agglutinin; 1.25 nM
[.sup.3H]-prostaglandin E.sub.2 as radioligand; 10 .mu.M
prostaglandin E.sub.2 as unlabelled ligand; a three-fold dilution
series of novel compound starting at 10 pM and ending at 0.3 nM is
adequate.
[0349] The following examples have a pK.sup.i of 6.0 or greater at
EP4 receptors as determined using the above-mentioned procedure:
[0350] 1, 4, 5, 8, 9, 12, 13, 14, 17.
* * * * *