REACTION OF 3,4-DICYANO-5-AMINOPYRAZOLE WITH ETHYL ORTHOFORMATEI730

Article abstract of DOI:10.1007/BF00506622

The condensation of 3,4-dicyano-5-aminopyrazole with ethyl orthoformate was studied.Under severe conditions (150 deg C) the principal reaction product is N-ethyl-3,4-dicyano-5-ethoxymethylaminopyrazole.Alkylation of the pyrazole ring does not occur at 100 deg C, but 3,4-dicyano-5-ethoxymethyleneaminopyrazole is formed.Isomeric 1-and 2-ethyl-4-aminopyrazolo<2,4-d>pyrimidine-3-carboxylic acid methyl imino esters were obtained by the action of a methanol solution of ammonia on the principal reaction product.This constitutes evidence that N-ethyl-3,4-dicyano-5-ethoxymethyleneaminopyrazole is a mixture of 1- and 2-ethyl- 3,4-dicyano-5-ethoxymethyleneaminopyrazoles.