Nucleophilic substitution and cyclization reactions involving quaternized 3-dimethylaminomethyl derivatives of 3,4-bis(indol-l-yl)maleimide and 3-(indol-l-yl)-4-(indolin-l-yl)maleimide

A dialkylaminomethylation reaction (the Mannich reaction) of 3,4-bis(indol-l-yl)-maleimides and 3-(indol-l-yl)-4-(indolin-l-yl)maleimides leads to mono- and di(dimethyl-amino) derivatives at position 3 of one or two indole rings. A series of 3,4-bis(indol-l-yl)-maleimides and 3-(indol-l-yl)-4-(indolin-l-yl)maleimides containing ω-hydroxyalkyloxy-methyl substituents at position 3 of the indole ring was obtained by the reaction of iodomethyl-ates of these compounds with ethylene glycol and other 6h,ω-alkanediols. The reaction of quaternary salts of bis(3-dimethylaminomethylindol-l-yl)maleimides with 6h,ω-alkanediols resulted in the isolation of 3,4-bis(3-ω-hydroxyalkyloxymethylindol-l-yl)maleimides. Upon heating iodomethylate of 3-(3-dimethylaminoindol-l-yl)-4-(indolin-l-yl)maleimide in pyridine, 5,6-dihydro-10-methyl- H -indolo[l′,7a′,7′:4,5,6]pyrrolo[3′,4′:2,3]-[l,4]diazepino[l,7- a ]-indole-l,3(2H)-dione was obtained due to the intramolecular alkylation and formation of the bond between position 2 of the indole and position 7 of the indoline rings.