Phosphoramides. XII. Diphosphorus Pentoxide Amine Mixtures as Reagents in a New Synthesis of Formamidines with Potential Pesticidal Activity.

Abstract
N''-Aryl-N,N-dialkylformamidines [a new class of specific acaricides] were prepared in a new synthetic manner by treating N''-arylformamides with a mixture of diphosphorus pentaoxide and an amine at 210.degree. C. The mechanism in these reactions is proposed to be the same as for the analogous hexamethylphosphoric triamide, HMPT, reactions. In the synthesis of N-aryl-N''-alkylformamidines using primary amines the yields were increased by using the corresponding amine hydrochlorides. The procedure was extended to acetamidines, propionamidines and benzamidines.