Synthesis and antimicrobial screening of 5<i style="">H</i>,7<i style="">H</i>-<i style="">N</i>-(coumarin-6-yl)-2,8-diphenyl-5,7-dioxo-4,5,6,7-tetrahydrobenzimidazo[5,6-<i style="">c</i>]­furan and 5<i style="">H</i>,7<i style="">H</i>-<i style="">N</i>-(coumarin-6-yl)-2,8-diphenyl-5,7-dioxo-6-(7-methoxy-4-methylcoumarin-6-yl)-4,5,6,7-tetrahydro benzimidazo[5,6-<i style="">c</i>]pyrrole

314-317The Schiff bases 2a-d of 6-aminocoumarins 1a-d on reaction with 4-benzylidene-2-phenyloxazolin-5-one in DMF and catalytic amount of pyridine afford 4-benzylidene-3-(coumarin-6-yl)-2-phenylimidazolin-5-ones 3a-d which on further Wittig reaction yield the corresponding 4-benzylidene-3-(coumarin-6-yl)-5-methylene-2-phenylimidazolines 4a-d. Compounds 4a-d on Diel’s-Alder reaction with maleic anhydride and N-(7-methoxy-4-methylcoumarin-6-yl)maleimide separately give 5H,7H-N-(cou­marin-6-yl)-2,8-diphenyl-5,7-dioxo-4,5,6,7-tetrahydrobenzi­mi­d­a­zo­(5,6-c)furans 5a-d and 5H,7H-N-(coumarin-6-yl)-2,8-diphenyl-5,7-dioxo-6-(7-methoxy-4-methylcoumarin-6-yl)-4,5,6,7-tetra­hydro­­benzimidazo(5,6-c)pyrroles 6a-d respectively. The structures of the compounds have been established on the basis of the spectral and analytical data. All the compounds 3-6a-d have been screened for their antimicrobial activities and found to exhibit significant antibacterial and antifungal activities