Synthesis of 2, 5-disubstituted 1, 3, 4-oxadiazoles as biologically active heterocycles

Abstract

<span style="font-size:12.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">2-(8enzimidazol-2'-yl) benzoyl hydrazide <b style="mso-bidi-font-weight:normal">1</b> when condensed with aromatic acids in the presence of POCI₃ afforded 2-aryl -5-[2'-benzimidazol-2"-yl) phenyl]-l, 3, 4-oxadiazoles <b style="mso-bidi-font-weight:normal">2a-o</b>. The acid hydrazide <b style="mso-bidi-font-weight:normal">1</b> on cyclisation with CNBr yield 2-amino-5-[2'-(benzimidazol-2 "-yl-phenyl)- 1, 3, 4-oxadiazole 3 which on reaction with aryl sulphonyl chlorides and substituted benzoyl chloride give the corresponding sulphonaillides <b style="mso-bidi-font-weight: normal">4a-o</b> and amides <b style="mso-bidi-font-weight:normal">5a-o</b>, respectively. All the products have been evaluated <i>in vitro </i>for their antimicrobial activity against several microbes and antitubercular activity against <i>Mycobacterium tuberculosis </i>H37Rv.</span>