Synthesis of spiro[indolo-1,5-benzodiazepines] from 3-acetyl coumarins for use as possible antianxiety agents

3-Acetyl coumarins (1) when allowed react with isatin (2) gave corresponding 3-(3´-hydroxy-2´-oxo indolo) acetyl coumarins (3), which on dehydration afforded the corresponding a,b-unsaturated ketones (4). Cyclocondensation of (4) with substituted o-phenylene diamines resulted in novel 3-coumarinyl spiro[indolo-1,5-benzodiazepines] (5). Structures of all the compounds have been established on the basis of their IR, NMR and mass spectral data and have been screened for their antimicrobial activity and antianxiety activity in mice.