Microwave assisted, one-pot synthesis of 5-nitro- 2-aryl substituted-1H-benzimidazole libraries: screening in vitro for antimicrobial activity.
The efficient and rapid synthesis of 5-nitro-2-aryl substituted-1H-benzimidazole libraries (1a-1j) has been established. Thus, both microwave and conventional cyclo-condensation of 4-nitro ortho-phenylenediamine with various phenoxyacetic acids were carried out in the presence of HCl catalyst. The microwave synthesis route afforded advantages, such as good to excellent yields, shorter reaction time (2.5-3.5 min), readily available starting material, and simple purification procedure, which distinguish the present protocol from other existing methods used for the synthesis of benzimidazole libraries. Bioassay indicated that all the compounds showed in vitro antimicrobial activity against Vancomycin resistant enteroccoccus, Staphylococcus aureus, Micrococcus, Bacillus subtilis (gram-positive bacteria) and Shigella dysentery, Escherichia coli (gram-negative bacteria) and Candida albicans, Aspergillus niger, Penicillium (fungi). The minimum inhibitory concentration (MIC) was determined for test compounds as well as for reference standards.
Hosamani
Kallappa Mahadevappa
KM
PG Department of Studies in Chemistry, Karnatak University, Pavate Nagar, Dharwad 580 003, India. dr_hosamani@yahoo.com
Seetharamareddy
Harisha Reddy
HR
Keri
Rangappa Sangappa
RS
Hanamanthagouda
Manohar Shirugumbi
MS
Moloney
Mark G
MG
D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001562:Benzimidazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D002384:Catalysis; D005658:Fungi / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D008872:Microwaves; D015394:Molecular Structure; D010407:Penicillium / Q000187:drug effects; D013210:Staphylococcus / Q000187:drug effects
D000890:Anti-Infective Agents; D001562:Benzimidazoles