| abstract |
1334705 Derivatives of 4-oxo-1,4-dihydroquinoline-2-carboxylic acid IMPERIAL CHEMICAL INDUSTRIES Ltd 19 May 1971 [19 June 1970] 29905/70 Heading C2C [Also in Division A5] The invention comprises (with numerous exceptions) compounds of formula wherein R<SP>1</SP> is H, Me or Et, R<SP>2</SP> is OH or C 1-6 alkoxy, and ring A may be substituted by 1 or 2 of C 1-5 alkyl and alkoxy, benzyl, benzyloxy, acetyl, halogen, CF 3 , NO 2 or NH 2 , or it may be fused with a 5,6- or 7,8-benzene ring, a methoxysubstituted benzene ring, or with (CH 2 ) 4 ; and their non-toxic pharmaceutically acceptable salts. In examples, the acids are prepared by hydrolysing the esters, which are in turn made by reacting a correspondingly substituted aniline with an ester of oxaloacetic or acetylenedicarboxylic acid, and heating the ester of 1-phenylaminoethylene-1,2-dicarboxylic acid so formed; exceptionally, an ester of the above formula containing an NH 2 substitute is prepared by reducing the corresponding nitrocompound. |