Synthesis of novel Indolyl benzo[b][1,4]diazepins as potent antimicrobial and antioxidant agents

A new series of novel indolyl benzo[b][1,4]diazepins bearing a 2,5-dichlorothiophene moiety are reported. Claisen-Schmidt condensation of 2,5-disubstituted indole-3-carboxaldehydes with 2,5-dichloro-3-acetylthiophene will produce (E)-3-(2,5-disubstituted-1H-indol-3-yl)-1-(2,5-dichlorothiophene-3-yl)prop-2-en-1-one. The acid catalysed cyclocondensation of preformed chalcones with substituted ortho-phenylenediamine has produced the titled compounds in good yields. All the newly synthesized compounds are characterised by IR, 1H NMR, 13C NMR, elemental analysis and mass spectroscopic data. Compounds 4b, 4c and 4f have emerged as most potent analogues in antimicrobial and antioxidant evaluations.