Reactions of amine hydrochlorides with phosphorus trichloride oxide; preparation and X-ray crystal structure of 2,4,6-trichloro-1,3,5-triphenyl-1,3,5,2λ5,4λ5,6λ5-triazatriphosphorinane 2,4,6-trioxide (PhNPOCl)3

Abstract

The reaction of aniline hydrochloride with POCl₃has been shown to yield the trimeric cyclophosphazane (PhNPOCl)₃in good yield and purity, in opposition to the earlier results of Michaelis which assigned a dimeric structure to the product. The trimeric nature has been confirmed by ³¹P n.m.r. spectroscopy, mass spectroscopy, and an X-ray crystallographic structure determination. The analogous 4-methylphenyl and 4-methoxyphenyl compounds have been similarly prepared. The products are relatively inert to nucleophiles but reactions with ethoxide and hydroxide ions yield products which give evidence for a mechanism involving ring contraction by transannular attack of nitrogen on phosphorus.