Chemoselective reactions of 3,6-diacetylindoles towards araldehydes, hydrazine hydrate and bromine: Synthesis and antimicrobial activity of novel 6-pyridyl/6-hydrazinoacetyl/6-bromoacetyl-3-acetylindole derivatives

1137-114

<span style="font-size:20.5pt;mso-bidi-font-size:14.5pt; font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">Synthesis and antimicrobial activity of novel 4<i style="mso-bidi-font-style:normal">H</i>-pyrano[2,3-<i style="mso-bidi-font-style:normal">f</i>]indole derivatives^†</span>

178-1825-Hydroxyindoles 1a-b have been subjected to regioselective Friedel-Craft 's acetylation to secure 3,6-diacetyl-5- hydroxyindoles 2a-b which on condensation with benzoic acids by using pyridine and phosphorous oxychloride furnish the required esters 3a-f in good yields. These esters 3a-f are subjected to Baker-Venkataraman transfomlations to obtain 3- acetyl-6-benzoylacetyl-5-hydroxyindoles 4a-f which are refluxed in AcOH and conc. HCI to afford the novel 2-phenyl-4H-pyrano[ 2,3-f]indol-4-one derivatives 5a-f. Similarly when 4a-f are heated with Ac2O and A<i style="mso-bidi-font-style: normal">cONa new 2-methyl-3-benzoyl-4H-pyrano[2,3-f]indol-4-one derivatives 6a-f are obtained. All these new compounds have been screened for their antibacterial and antifungal activities.</span

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