Synthesis and antimicrobial activity of some new 1-cyclohexyl-3-carbethoxy-2-methyl-5- oxadiazolyl/triazolyl and pyrrolylaminocarbonylmethoxyindoles

Abstract

The exclusive formation of 1-cyclohexyl-3-carbethoxy-2-methylindol-5-yloxyacctic acid hydrazide <b>3</b> when 1-cyclohexyl-3-carbethoxy-5-methoxycarbonylmethoxy-2-methylindole <b>2</b> is reacted with hydrazine hydrate, reveals the chemoselectivity of C₅-ester over C₃-carbethoxy ester function towards the nucleophilic attack of hydrazine hydrate. This monocarbohydrazide was treated separately with triethylorthoformate, acetonylacetone in

boiling absolute ethanol, CS₂/KOH and further on acidification with HCl, CS₂/KOH followed by treatment with hydrazine hydrate, KCNS/HCl and treatment with 10% NaOH, to furnish 1-cyclohexyl-3-carbethoxy -2-methyl-5-(1,3,4-oxadiazol-2-yl) methoxyindole

<b>4</b>, 1-cyclohexyl-3-carbethoxy-2-methyl-5-(2,5-dimethylpyrrol-1-yl) aminocarbonylmethoxyi ndole <b>5</b>, 1-cyclohexyl-3-carbethoxy-2-methyl-5-(5-mercapto-1 ,3,4-oxadiazol-2-yl) methoxyindole <b>6</b> and 1-cyclohexyl-3-carbethoxy-2-methyl -5-(4-amino-5-mercaptotriazol-3-yl)methoxyindole <b>7</b> and 1-cyclohexyl-3-carbethoxy-2-methyl-5-(4<i>H</i>-5-mercapto-1,2,4-triazol-3-yl)methoxyindole <b>8</b>, respectively. The newly synthesized compounds have been evaluated for their antimicrobial activity and their structures have been confirmed on the basis of analytical and spectral data.