Nontraditional approaches to the synthesis of some biologically active substituted <Emphasis Type="Italic">p</Emphasis>-benzoquinones

The condensation of mono o- or p-substituted anilines (1) with tetrachloro-1,4-benzoquinone (2) has been achieved by using K₂CO₃ under conventional heating, solid solvent-free grinding, solid-phase microwave irradiation (MWI) conditions to obtain substituted dichloro-p-benzoquinone derivatives (3). All the nontraditional methods described herein provide several advantages over prior methods such as higher yield, convenient work-up procedure, and enviro-economic synthesis. It is observed that solid-supported reaction under MWI is the most appropriate for the synthesis of the title compounds. All the synthesized compounds were tested for their in vitro antibacterial and antifungal activity. Some compounds showed promising antimicrobial properties. The best activity was observed with compounds 3b and 3f. Presented at the International Symposium on Current Trends in Drug Discovery Research (CTDDR) (P-12) 17–21 February 2007, Central Drug Research Institute, Luknow, India. (Abstract Published in Medicinal Chemistry Research 2007, 15(1/6):117–118).