Abstract:

Benzodiazepines are an important class of heterocyclic compounds with diverse pharmacological activities, including anticonvulsant, anti inflammatory, analgesic, hypnotic, sedative, and anxiolytic properties. Beyond their therapeutic relevance, 1,5 benzodiazepine derivatives serve as intermediates for the synthesis of fused heterocyclic systems and find industrial applications as dyes and in photographic processes. Conventional synthetic methods often suffer from harsh conditions, long reaction times, and limited yields, highlighting the need for greener alternatives.In this study, phosphomolybdic acid (PMA) was employed as a recyclable and environmentally benign catalyst for the one pot, three component synthesis of ethyl 4 methyl 2 phenyl substituted 2,3 dihydro 1H 1,5 benzodiazepine 3 carboxylate derivatives. The method proved operationally simple, affording excellent yields (97–98%) within short reaction times (30–50 minutes) under mild conditions. Spectral characterization (FT IR, ¹H NMR) confirmed the structures, while antibacterial screening revealed promising activity, particularly for the 2 phenyl derivative (1a), which showed inhibition zones approaching ciprofloxacin against both Gram positive and Gram negative strains.The antibacterial activity observed for compounds 1a–1c suggests potential pharmacological applications, positioning benzodiazepine scaffolds as promising leads for new antimicrobial agents. Recent advances in micellar catalysis and phosphomolybdic acid applications further validate the efficiency and sustainability of this approach, offering a green and practical route to biologically relevant benzodiazepines with pharmaceutical potential.