Reaction of alkylidenemalononitriles with diazomethane

Abstract

At −15° C isopropylidenemalononitrile (5) reacts with anequimolar amount of diazomethane to yield the pyrazoline8, which loses nitrogen upon heating, to give 2,2-dimethyl-1,1-cyclopropanedicarbonitrile (9), and 2-butylidenemalononitrile (6). At room temperature with anexcess of diazomethane5 gives a number of homologous 2-methyl-2-n-alkyl-1,1-cyclopropane-dicarbonitriles9–13 via the corresponding homologous alkylidenemalononitriles, as supported by the similarity of products obtained from the reaction of 2-pentylidenemalononitrile (7) and diazomethane.