Synthesis, anti-bacterial, anti-asthmatic and anti-diabetic activities of novel N-substituted-2-(benzo[d]isoxazol-3-ylmethyl)-1H-benzimidazoles

Synthesis of a series of novel class of N-substituted-2-(benzo[d]isoxazol-3-ylmethyl)-1H-benzimidazoles (4) by the condensation of o-phenylenediamine (1) with benzo[d]isoxazol-3-yl-acetic acid (2) and subsequent reactions with different types of electrophiles have been reported. Some compounds exhibited promising anti-bacterial activity against Salmonella typhimurium, however poor activity against Staphylococcus aureus. The compound 4t was found to have high activity even at 1 mu g/ml compared to Cephalexin against S. aureus. The biological activity against PDE-IV for potential anti-asthmatic effect and against DP-IV and PTP-1B for potential anti-diabetic effects was disappointing.