INFLUENCE OF DICHLOROACETYLATION ON THE ANTIMICROBIAL ACTIVITY OF CHLORAMPHENICOL DERIVATIVES AND OF VARIOUS AMINES

The dichloroacetyl group, one of the functional groups responsible for the anti‐bacterial activity of chloramphenicol, has been inserted into various amines, and the dichloroacetamido‐derivatives obtained have been studied against E. histolytica EdM, Candida albicans ATCC 2091, Saccharomyces cerevisiae ATCC 7921, Aspergillus niger NRRL 3, Trichomonas vaginalis and Mycobacterium tuberculosis H37Rv and ATCC 607. Among the various chlorophenoxamide analogues, only N‐(benzothiazol‐2‐ylmethyl)dichloro‐N‐2‐hydroxyethylacetamide shows an activity, in vitro and in vivo, comparable with that of chlorophenoxamide. The dichloroacetyl group is essential for the high amoebicidal activity in vivo of chlorophenoxamide. The dichloro‐acetamidopropiophenones of known antifungal activity also show marked amoebicidal activity in vitro, but they appear to have a different mechanism of action from chloro‐phenoxamide since the dichloroacetyl group is not indispensable. The high anti‐tubercular activity of some benzothiazole derivatives is not increased by dichloro‐acetylation.