We recently described the reaction of 2, 3, 3-trimethylindolenines (3H-indoles) 1 with the Vilsmeier reagent formed from dimethylformamide and phosphorus oxychloride to produce aminomethylene malondi-aldehydes 2 [1, 2]. Additionally, we showed that these intriguing polyfunctional compounds reacted well with hydrazine or arylhydrazines to produce 4-(3, 3- dimethyl-3H-indol-2-yl)-substituted pyrazoles, 3, with migration of the double bond into the ...