Chemoselective reaction of benz[g]indole dicarboxylate towards hydrazine hydrate:Bisheterocycles:Synthesis and antimicrobial activity of some new l-[2-hydroxyethyl]-3-ethoxycarbonyl-5-oxadiazolyl/triazolyl/pyrrolylaminocarbonylmethoxy-2-methylbenz[g]

摘要

The exclusive formation of l-[2-hydroxyethyl]-3-ethoxycarbonyl-2-methyl benz[g] indol-5-yloxyacetic acid hydrazide 6 from l-[2-hydroxyethyl]-3-ethoxycarbonyl-5-methoxycarbonylmethoxy-2-methylbenz[g]indole 3 revealed the chemo-selectivity of the C_5-ester over C_3-ester towards nueleophilic attack of hydrazine hydrate.This monocarbohydrazide 6 is reacted separately with CS_2/KOH,acetonyl acetone and isothiocyanates to secure the desired l-[2-hydroxyethyl]-3-ethoxycarbonyl-5-(5-mercapto-l,3,4,-oxadiazl-2-yl)methoxy-2-methylbenz[g]indole 7,l-[2-hydroxyethyl]-3-ethoxy-carbonyl-5-(2,5-dimethylpyrrol-l-yl)aminocarbonylmethoxy-2-methylbenz[g]indole 8 and l-[2-hydroxyethyl]-3-ethoxycarbonyl-5-(N-substituted thiosemicarbazinocarbonyl)methoxy-2-methylbenzfg]indole 9a-c.These thiosemicarbazides 9a-c are reacted with 4% NaOH to produce the l-[2-hydroxyethyl]2-methybenz[g]indol-5-(4-substituted-5-mercapto-l,2,4-triazol-3-yl)methoxy-3-caboxylic acids 10a-c.All theses newly synthsised compounds are screened for their antimicrobial activities.