Synthesis and antimicrobial activity of some new 1-substituted-3-pyrrolyl aminocarbonyl/oxadiazolyl/triazolyl/5-methoxy-2-methylindoles and benz[<i>g</i>]indoles

Abstract

1-Substituted-5-methoxy-3-carbethoxy-2-methylindoles <b style="">2a-c</b> on reaction with hydrazine hydrate in ethyl alcohol give back the starting materials <b style="">2a-c</b>. Then ethylene glycol is used as solvent instead of ethyl alcohol in the above reaction and obtained conveniently the desired 1-substitured-5-methoxy-3-hydrazinocarbonyl-2-methylindoles <b style="">3a-c</b> and they are further reacted separately with acetonyl acetone; carbon disulphide and alcoholic potassium hydroxide; followed by hydrazine hydrate; allyl isothiocyanate and phenyl isothiocyanate to obtain the desired 1-substituted-5-methoxy-3-(2,5-dimethylpyrrol-1-yl)amino carbonyl-2-ethyl-indoles <b style="">4a-c</b>, 1-substituted-5-methoxy-3-(5-mercapto-1,3,4-oxadiazol-2-yl) 2-methylindoles <b style="">5a-c</b>, 1-substituted-5-methoxy-3-(4-amino-5-mercapto-1,2,4-triazol-3-yl)-2-methylindoles <b style="">6a-c</b>, 1-substituted-5-methoxy-3-(<i>N-</i>allylthiosemicarbazinocarbonyl)-2-methylindoles <b style="">7a-c </b>and 1-sustituted-5-methoxy-3-(<i>N</i>-phenylthiosemicarbazino­carbonyl)-2-methyl indoles <b style="">8a-c</b> respectively. The thiosemicarbazides <b style="">7a-c</b> and <b style="">8a-c</b> are heated with 4% NaOH to secure 1-substituted-3-(4-allyl-5-mercapto-1, 2,4-triazol-3-yl)-5-methoxy-2-methylindoles <b style="">9a-c</b> and 1-substituted-3-(4-phenyl-5-mercapto-1,2,4-triazol-3-yl)-5-methoxy-2-methylindoles <b style="">10a-c</b> respectively. Similar set of reactions are also carried out on 1-furfuryl-3-carbethoxy-5-methoxy-2-methylbenz[<i>g</i>]indole <b style="">12.</b> Structures of all these newly synthesised compounds are confirmed by their spectral and analytical data and the compounds are also screened for their antibacterial and antifungal activities.