Synthesis of diphenyl bisamidines as potential amoebicides

Chemistry and Biology of Synthetic and Naturally Occurring Antiamoebic Agents

“…Further bicyclic amidines have been identified as highly active acylation catalysts . Venugopalan et al synthesized various substituted diphenyl bisamidines 2.059 by the reaction of substituted benzidines 2.057 with pyrrolidines 2.058 at 100 °C in the presence of POCl 3 with 10−52% yields (Scheme ) . The substituted pyrrolidones 2.058 were prepared earlier by other research groups. − Michael addition of the carbanions, generated from nitro alkanes with acrylate in the presence of Triton B, gave the adducts that underwent catalytic reduction in the presence of Raney Ni in ethanol followed by heating at 50 °C, to yield the substituted pyrrolidones 2.058 .…”

“… a Highest dose tested and was inactive. b Approximate ED 50 . c 100% effective dose. (Reprinted with permission from ref . Copyright 1996 Elsevier Science Ltd.) …”