Abstract

SYNTHESIS AND BIOLOGICAL EVALUTION OF NEWER DERIVATIVES OF QUINOXALINES

Sharanagoud Biradar* and Dr. Ramaling B. Kotnal

ABSTRACT

Naturally occurring compounds contain quinoxaline ring and proven to have several biological activities. Quinoxaline is also known as benzopyrazine. Quinoxalines containing both benzene and pyrazine ring. Cyclization of o-phenylinediamine was carried out with ethyl pyruvate in presence of n-butanol. The product obtain was recrystalized from ethanol. Then chlorination reaction was carried out by using POCl3. Then reacted with salicyladehyde in acetonitrile to obtained intermediate compounds. The intermediate product was reacted with different anilines to obtain title compound, viz., SSB-QMNA, SSB-QXPAP, SSB-QXPMA, SSB-QXOMA, and SSB-QXPNA. These compounds were tested for antibacterial activity against E. coli (gram negative) and Staphylococcus aureus (gram positive) using cup plate method. Compounds showed significant activity at concentration of 500μ/ml and 750μ/ml, Chloramphenicol was used as reference standard drugs. The compounds were analyzed by IR, 1H NMR, 13C NMR and Mass spectrum.

Keywords: o-phenylinediamine, Ethyl pyruvate, n-butanol, POCl3, Acetonitrile, Salicyladehyde, Ethanol, Aniline derivatives and Antibacterial activity.