Studies on Chemotherapeutics for Mycobacterium tuberculosis. IX

Synthesis and Antibacterial Activity of 2-o-Hydroxybenzylidenehydrazono-4-thiazolidone and Its Related Compounds. (4)

Abstract

2-o-Hydroxybenzylidenehydrazono-4-thiazolidone and its 5-substituted derivative possess strong antibacterial action against the tubercle bacilli but their allied compounds in which no hydroxyl group is present in the ortho-position of the benzene ring are weak in such action. Allied compounds possessing allyloxyl, bromo, or carboxyl group in the ortho-position were prepared and their antibacterial action was tested but they all had only a weak activity, especially those with the carboxyl group. The compounds (II) to (V) in Table I were obtained by the usual method of condensing aldehyde thiosemicarbazones with ethyl chloroacetate or ethyl α-bromopropionate. 2-o-Carboxybenzylidenehydrazono-4-thiazolidone (VI) was obtained from 2-α-methylbenzylidenehydrazono-4-thiazolidone by decomposition with hydrochloric acid to 2-hydrazono-4-thiazolidone hydrochloride, followed by application of phthalaldehydic acid.