Abstract: Benzimidazole derivatives of the formula (I): ##STR1## or a pharmaceutically acceptable acid addition salt thereof wherein R.sup.1 is hydrogen or lower alkyl; R.sup.2 is ##STR2## or --C.tbd.C--Ar wherein Ar is phenyl unsubstituted or substituted by one to three substituents selected from the group consisting of halo, lower alkyl, hydroxy, unsubstituted or substituted lower alkoxy, aralkyloxy wherein the alkyl moiety is a lower alkyl moiety, lower alkenyloxy, lower alkynyloxy, difluoromethoxy, lower alkylamino, methylenedioxy, trifluoromethyl, cyano, lower alkylthio and lower alkylsulfinyl; R.sup.4, R.sup.5, R.sup.6 and R.sup.7 a hydrogen or lower alkyl or R.sup.4 and R.sup.5 together with the carbon atoms to which they are attached form a cyclopropyl ring; and R.sup.3 is hydrogen, lower alkyl, acyl or lower alkylsulphonyl are useful in the treatment of ulcers of the stomach and duodenum in humans and animals.

Abstract: Quinolinecarboxylic acid derivatives, such as compound 7-fluoro-8-(4-methyl-1-piperazinyl)-5-oxo-1,2-dihydro-5H-thiazolo(3,2-a)-q uinoline-4-carboxylic acid, a pharmaceutical composition containing the same and methods of treatment of bacterial and fungal infections using the same.