Kc. Joshi et al., INVESTIGATION OF THE REACTION OF INDOLE-2,3-DIONES WITH BENZAMIDINE HYDROCHLORIDE, Indian journal of chemistry. Sect. B: organic chemistry, including medical chemistry, 31(4), 1992, pp. 280-281
Reaction of simple and N-substituted 3-dicyanomethylene/carboethoxy cy
anomethyleneindole-2-ones-(II) with benzamidine hydrochloride has been
carried out with a view to studying the effect of substitution on ind
olyl nitrogen. The results indicate that unsubstituted indole derivati
ves afford two products, a spiro system, -3,4'(3'H)-pyrimidine]-5'-car
bonitriles/carboxylic acid ethyl esters(III( and a fused system [1,3]d
iazepino [4,5]indole(IV),N-Alkylated analogs, however, under identical
conditions, afford the spiro system exclusively.