Efavirenz Mannich bases: Synthesis, anti-HIV and antitubercular activities

A series of efavirenz Mannich bases has been synthesized by reacting efavirenz, formaldehyde, and various aryl substituted piperazines using microwave irradiation (yield 35–88%). The synthesized compounds were evaluated for in-vitro anti-HIV and antimycobacterial activities. The in-vitro antiretroviral activities indicated that compound 7-(4-((6-chloro-4-(2-cyclopropylethynyl)-4-(trifluoromethyl)-2-oxo-2H-benzo[d] [1,3]oxazin-1 (4H)-yl)methyl)-3-methylpiperazin-l -yl)-1-cyclopropyl-6-fluoro-l,4-dihydro-8-methoxy-4-oxoquinoline-3-carboxylic acid (4i) was equipotent to efavirenz with EC50 of 2.4 nM. Compound 4i also inhibited M. tuberculosis with minimum inhibitory concentration of 0.2 μg/mL.