Novel Linezolid like Analogues: Synthesis, Characterization and Biological Evaluation

Abstract

The synthesis of 4-(substituted benzylidene)-2-(pyrazin-2-yl) oxazol-5(4<em>H</em>)-one was achieved in two steps, In first step, pyrazine-2-carboxamide dissolved in EtOH, 10% KOH solution with ClCH₂COOH produced compound 2-(pyrazine-2-carboxamido) acetic acid (II) and in second step, compound (II) in (CH₃CO)₂O with aromatic aldehyde, and catalyst potassium acetate produced title compounds 4-(substituted benzylidene)-2-(pyrazin-2-yl) oxazol-5(4<em>H</em>)-one (PA1-PA14). All the newly synthesized compounds structure were elucidated using various spectral techniques viz. FT-IR, ¹H-NMR, GC-MS spectroscopy, and CHN elemental analysis data and screened for <em>in vitro</em> antimicrobial and antifungal activity. <em>In vitro</em> anti bacterial activity was carried out against organisms <em>E.coli, K.pneumonia, S.aureus</em>, and <em>B. Subtilis</em> as well as antifungal activity were carried out against <em>A.niger</em> and <em>S.cerevisiae</em> activity byminimum inhibitory concentration method. The most promising broad spectrum compounds PA3, PA4, and PA5 were observed and study data reveals that additions of different functional groups had varying effects on activity. In addition, the greater biological activities were observed when the electron-withdrawing groups like fluorine, bromine and chlorine were incorporated at <em>p</em>-position of the phenyl ring.