Patent GB-1164923-A (GB)
Title: Novel Indole Derivatives, their Preparation and Compositions Containing them.
IPC: C07D209/30
Filed: 1967-06-27
Abstract: 1,164,923. α-(3-Indolyl)-carboxylic acid derivatives. MERCK & CO. Inc. 27 June, 1967 [29 June, 1966], No. 29635/67. Heading C2C. Novel α-(3-indolyl)-carboxylic acid derivatives of the general formula wherein A is an aromatic homocyclic or heterocyclic substituted or unsubstituted carboxylic acyl radical of less than 3 fused rings; X is oxygen or sulphur; R 2  is hydrogen or a C 1-5  alkyl, aryl, C 1-5  aralkyl, (C 1-5  alkyl) aryl or C 3-6  cycloalkyl radical; R 3  is hydrogen or an amino, C 1-5 -alkylamino or di-(C 1-5  alkyl)-amino or C 1-6  alkyl radical; R 4  is hydrogen, a halogen or a C 1-5  alkyl, C 1-5  alkoxy or trifluoromethyl radical; R 5  is hydrogen, C 1-5  alkyl, C 1-5  alkoxy, nitro, amino, C 1-5  alkylamino, di-(C 1-5  alkyl)-amino, haloalkyl, C 1-6  alkanoylamino, C 1-6  alkanoyl, bis-(hydroxy- C 1-5  alkyl)-amino, 1-pyrrolidinyl, 4-methyl-1- piperazinyl, morpholino, cyano, amino- C 1-5  alkyl, di-(C 1-5  alkyl)-amino-C 1-5  alkyl, trifluoromethyl, hydroxyl, a halogen, di-(C 1-5  alkyl) sulphamoyl, benzylthio, benzyloxy, C 1-5  alkyl-benzyloxy, C 1-5  alkoxybenzyloxy, C 2-5  alkenyl, C 2-5  alkenyloxy, cyclopropyl, 1-azacyclopropyl, cyclopropyl-C 1-5  alkoxy or cyclobutyl- C 1-5 alkoxy; and M is a hydroxyl, amino, C 1-5  alkylamino, di-(C 1-5  alkyl)-amino, C 2-5  alkenylamino, (aryl-C 1-5  alkyl) amino, arylamino, haloarylamino C 1-5  alkoxy, C 2-5  alkenyloxy, C 2-5  alkynyloxy, aryloxy, a substituted or unsubstituted cyclo-alkoxy, or cyclo-alkenyloxy radical of not more than 6 carbon atoms, a substituted or unsubstituted cyclo, alkynyloxy radical; OZ wherein Z is a cation; or OY wherein Y is represented by the formula are prepared (i) when R 2  and R 3  are each hydrogen, X is oxygen and M is hydroxyl, by (a) reacting an aniline with a haloacetic acid to form an oxindole, (b) treating said oxindole with a dibasic oxalate to produce an isatylidenehydroxy α-lower aliphatic ester; (c) hydrogenating said ester to an oxindolyl acetic ester; (d) acylating said oxindolyl ester with an aromatic homocyclic or heterocyclic substituted or unsubstituted carboxylic acyl group of less than three fused rings; and (e) converting said acylated oxindolyl ester to the corresponding acid: (ii) when R 3  is hydrogen or C 1-6  alkyl, X is sulphur, R 2  is hydrogen and M is hydroxyl, by (a) reacting a γ-acetal of a C 1-6  aliphatic acid with a phenylhydrazine to form a 3-indole ether; (b) removing the protecting ether group to form the corresponding 3-indole alcohol; (c) re-etherifying said alcohol; (d) treating the resulting ether with a Grignard reagent to produce a 2-magnesylindole ether; (e) reacting said 2-magnesylindole ether with sulphur and an acylating agent, followed by an alkali, to form a 2-mercapto ether; (f) acylating said 2-mercapto ether or an S-protected derivative thereof with an aromatic homocyclic or heterocyclic substituted or unsubstituted carboxylic acyl group of less than three fused rings; (g) regenerating the 3-indolylalchol; and (h) oxidizing the regenerated alcohol to the corresponding aldehyde and thence to the acid and removing any S-protecting group: (iii) when R 2  is hydrogen, R 3  is C 1-5  alkyl, X is oxygen and M is hydroxyl, by (a) reacting an aniline with a haloacetic acid to form an oxindole; (b) treating said oxindole with an α-olefinic C 3-6 -aliphatic acid to produce an α-(alkyl-substituted)-isatylidene acetic acid ; (c) esterifying the isatylidene acid with a C 1-5  alkanol or aralkanol; (d) hydrogenating the resulting isatylidene C 1-5  aliphatic ester to the corresponding α-(alkyl-substitzited) oxindole acetic ester; (e) acylating said ester with an aromatic homocyclic or heterocyclic substituted or unsubstituted carboxylic acyl radical of less than three fused rings; and (f) converting the acylated oxindole ester to the corresponding acid: (iv) when R 3  is C 1-5  alkyl, R 2  is other than hydrogen and X is oxygen, by the process of (iii) steps (a) to (e), followed by (f) reacting the resulting acylated ester with an alkali metal; and (g) treating the obtained salt with a hydrocarbon halide to produce an α-(1-acylated-2- hydrocarboxy-3-indolyl) α-(alkyl-substituted)- acetic ester, followed optionally by hydrolysing this ester to the corresponding acid, ammonolysing the ester to the corresponding amide or reacting the ester with a base ZOH or a compound YHal wherein Hal is a halogen: (v) when R 3  is NR<SP>02</SP> and R 2  is R in which R is C 1-5  alkyl, M is as defined in the general formula above except that it is not hydroxy, amino, substituted amino, OZ or OY, and X is oxygen, by (a) reacting an aniline with a haloacetic acid to form an oxindole; (b) treating the oxindole with an oxalic acid compound to form the corresponding α-keto oxindole acetic compound; (c) reducing the α-keto oxindole acetic compound via the oxime to an α-amino product; (d) forming a tertiary amine by reacting the α-amino product with an alkyl halide; and (e) acylating the tertiary amine with an aromatic homocyclic or heterocyclic substituted or unsubstituted carboxylic acyl radical of less than three fused rings: or (vi) when R 2  is C 1-5  alkyl, aryl, ar-C 1-5 -alkyl or C 1-5  alkylaryl, R 3  is hydrogen or C 1-5  alkyl, X is sulphur and M is hydroxyl, by (a) reacting a phenylhydrazine with a γ-aldehyde C 1-5  aliphatic ester to form an indolyl ester; (b) acylating said indolyl ester with an aromatic homocyclic or heterocyclic substituted or unsubstituted carboxylic acyl group of less than three fused rings; (c) hydrolysing the obtained acylated indolyl ester to the corresponding indolyl acid; and (d) treating the indolyl acid with an alkyl sulphinyl halide. Pharmaceutical compositions having antiinflammatory and anti-pyretic activity comprise as active ingredient, an α-(3-indolyl)-carboxylic acid derivative of the above general formula and an inert, non-toxic diluent, carrier or coating, and may be administered orally or parenterally.