1,5-benzodiazepine derivatives of 3-arylsydnones: synthesis and antimicrobial activity of 3-aryl-4-[2'-aryl-2',4',6',7'-tetrahydro-(1'H)-1',5'-benzodiazepine-4' -yl]sydnones.

The alpha-beta-unsaturated ketones of 3-arylsydnones (Ia-y) were treated with 1,2-phenylenediamine to obtain the 3-aryl-4-[2'-aryl- 2',4',6',7'-tetrahydro-(1'H)-1',5'-benzodiazepine-4'-yl]sydnones (IIa-y) in high yield. All the new compounds synthesised were screened for antibacterial and antifungal activities.

Transformation of the sydnone ring into oxadiazolinones. A convenient one-pot synthesis of 3-aryl-5-methyl-1,3,4-oxadiazolin-2-ones from 3-arylsydnones and their antimicrobial activity.

3-Arylsydnones (Ia-u) have been converted into the corresponding 3-aryl-5-methyl-1,3,4-oxadiazolin-2-ones (IIIa-u) by a single-step reaction with bromine in acetic anhydride. In the preliminary screening of all these compounds, the halogen-substituted derivatives have shown antimicrobial activities equal to those of the standard drugs used.