CHEMOTHERAPEUTIC STUDIES ON SCHISTOSOMIASIS Ⅹ.SOME AMIDES DERIVED FROM THIOPHENE-2-CARBOXYLIC,THIOPHENE-2-SULPHONIC ACID AND TETRAHYDROTHIOPHENE-2,5-DICARBOXYLIC ACID

It has been discovered in our Institute that Cucurbitine (Ⅰ) is an effective inhibitor against Schistosoma japonicum. In order to find chemical analogues which are more powerful inhibiting agents, various amides of thiophene-2-carboxylic acid, thiophene-2-sulphonic acid and tetrahydrothiophene-2, 5-dicarboxylic acid have been prepared. But none of these compounds was active on animal test. Oxidation of thiophene-2-formaldehyde by means of silver oxide gave thiophene-2-formic acid. On treating thiophene-2-formyl chloride and thiophene-2-sulphonyl chloride with various amines, the corresponding amides were readily formed. Reduction of N, N'-bis-(thiophene-2-carbonyl) piperazine by means of lithium aluminium hydride gave N, N'-bis-(thiophene-2-methyl) piperazine. Cis-tetrahydrothiophene-2,5-dicarbonyl chloride was formed when cis-tetrahydrothiophene-2, 5-dicarboxylic acid was treated with thionyl chloride. Cis-tetrahydrothiophene-2, 5-dicarbonyl chloride on treatment with aqueous ammonia and β-phenylethylamine gave 2, 5-dicarbamyltetrahydrothiophene and N, N'-bis-(β-phenylethyl)-2, 5-dicarbamyltetrahydrothiophene respectively.