Studies with enaminonitriles : Synthesis and chemical reactivity of 2-phenyl-3-piperidin-1-yl acrylonitrile under microwave heating

Benzyl cyanide reacts with triethylorthoformate and piperidine in DMF solution to yield the title compound 2. This reacted with aromatic amines to yield either aminoacrylonitriles or quinoline depending on reaction conditions and substitution pattern on the aromatic amine. The reaction of compound 2 with hydrazine hydrate could only be effected in the microwave oven and resulted in the formation of aminopyrazole 7. Diazotization of 7 and coupling with an active methylene reagent afforded pyrazolo[5,1-c]-[1,2,4]triazine derivatives.