Reaction of Phenyllithium with Some N,N -Disubstitiited Cyanamides

Abstract

Phenyllithium adds to N,N-dialkylcyanamides 1 to form, successively, the metal salts of the amidines 3 and the guanidinylamidines 5 followed by further addition and ring closure to give the phenyl-1,3,5-triazines 8. This proposed course of the reaction is supported by the isolation of intermediates, and compounds derived from them, as well as by determination of product yields with varying ratio of reactants. It appears that 2-thienyllithium reacts similarly with dimethylcyanamide. The reaction of phenyllithium with N-methyl-N-phenylcyanamide gives mostly the tetrasubstituted cyanoguanidine 10.