PROCESS FOR PRODUCING QUINOLINECARBOXYLIC ACID DERIVATIVES

PCT No. PCT/HU87/00044 Sec. 371 Date Jun. 3, 1988 Sec. 102(e) Date Jun. 3, 1988 PCT Filed Oct. 14, 1987 PCT Pub. No. WO88/02748 PCT Pub. Date Apr. 21, 1988.The invention relates to a new and simple process for the preparation of quinoline-carboxylic acid derivatives of the general formula (I) (I) as well as hydrates and therapeutically acceptable salts thereof. In the formula the meaning of the substituents is as follows: R is hydrogen atom or a formyl group, R1 is a hydrogen atom or a straight or branched chain alkyl group having 1 to 4 carbon atoms, which may be substituted by a hydroxyl group, a halogen atom or an amino group; or a CH3-NH-group, R2 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. According to the invention the compound of the general formula (II) (II) or an acid addition salt thereof is reacted with piperazine in dimethylformamide and-if desired-the compound of the general formula (III) (III) thus obtained is subjected to an acidic or alkaline treatment, or is reacted advantageously with hydrazine or preferably with hydrazine-hydrate.