Synthesis of pyrazolo[1,3,2]diazaphosphinin‐4‐ones

Abstract

Abstract It was found that phosphinimidic isocyanates based on 3‐, 4‐, and 5‐aminopyrazoles could undergo intramolecular heterocyclization to yield previously unknown pyrazolo[1,3,2]diazaphosphorin‐4‐ones containing an endocyclic PN double bond. It was shown that phosphinimidic isocyanate based on 4‐aminopyrazole, in which there are two positions (3 and 5) available for the cyclization, reacts exclusively at the 5‐carbon atom. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:210–215, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21005