Chemoselectivity of bisindole tetracarboxylate towards hydrazine hydrate:Synthesis and antimicrobial activity of diethyl 5,5'-bis(2,5-dimethylpyrrol-1-ylaminocarbonylmethoxy)-2,2' -dimethyl-1, l' -(ethane-1,2-diyl)di(1<i>H</i>-indole )-3,3'-dicarboxylate

Abstract

31-35Diethyl 5,5' -dihydroxy-2,2'-dimethyl-1,1' -(ethane-1,2-diyl)di(1H-indole)-3,3'-dicarboxylate 3 has been prepared in one-flask procedure by the condensation of diethyl 3,3'-(ethane-2,2' -diyldiimino )butenoate 1 with 1,4-benzoquinone 2 in 1:2 molar ratio. Reaction of 3 separately with methyliodide and ethyl chloroacetate affords the corresponding O-alkylated derivatives 4 and 5, respectively. Exclusive formation of diethyl 5,5'-bi-(hydrazinocarbonylmethoxy)-2,2' -dimethyl-1,1'(ethane-1,2-diyl)di(1H-indole)-3,3'-dicarboxylate 6 from 5 reveals the chemoselectivity of 5,5'-ester function towards nucleophilic attack of hydrazine hydrate. This dicarbohydrazide 6 on reacting with acetonylacetone furnishes diethyl 5,5-'bis(2,5-dimethylpyrrol-l-ylamino-carbonylmethoxy)-2,2' -dimethyl-1,1'-(ethane-1,2-diyl)di(1H-indo le)-3,3'-dicarboxylate 8.Conformations of all these bisindole derivatives have been established. Compounds 3, 4, 5, 6 and 8 have also been screened for their antibacterial and antifungal activities