Synthesis and biological activity of new diarylalkenes

Condensation of 5-nitro, 3-chloro-, and 5-chlorosalicylic acid with formaldehyde afforded dimeric disalicylmethanes which were O-methylated with dimethyl sulfate and oxidized with chromium(VI) oxide to give the diarylketones 10, 11, 12. Wittig reaction with ylides obtained by deprotonation of alkyltriphenylphosphonium salts with sodium bis (trimethylsilyl)amide yielded a series of diarylalkenes. Some of the obtained compounds showed high antimicrobial activity in vitro against Bacillus subtilis and Mycobacterium smegmatis.