Synthesis and antimicrobial activity of novel 5-tetrazolyl/oxadiazolyl/benzimidazolylmethoxyindole derivatives

188-1911-Alkyl-3-acetyl-2-methylindol-5-yloxyacetonitriles 2a,b, prepared by reacting 5-hydroxyindoles 1a,b with chloroacetonitrile have been converted to 1,2,3,4-tetrazolylindoles <b style="mso-bidi-font-weight: normal">3a,b using NaN3. <span style="font-size:14.0pt; mso-bidi-font-size:8.0pt">LiCI and NH<span style="mso-bidi-font-size: 6.0pt">4C1 in dry dimethylformamide. Conversion of tetrazolylindoles 3a,b into 1,3,4-oxadiazolylindoles 4a,b has been achieved by heating with acetic anhydride. Hydrolysis of 1-alkyl-3-ethoxycarbonyl-5-ethoxycarbonylmethoxy-2-methylindoles 5a,b with ethanolic NaOH gives the corresponding diacids 6a,b, which on heating with o-phenylenediamine in 6N HCI undergo condensation with concomitant decarboxylation to yield the 1-alkyl-5-(benzimidazol-2-ylmethoxy)-2- methylindoles 7a,b. The newly synthesised bisheterocycles have been screened for their antibacterial and antifungal activities.</span