Phosphorus–nitrogen compounds. Part XXXVIII. Reactions of phenylphosphonic dichloride and phenylphosphonothioic dichloride with di-benzylamine

Abstract

PhP(O)Cl₂(1) reacts with dibenzylamine in organic solvents at room temperature to give PhP(O)[N(CH₂Ph)₂](OEt)(3), PhP(O)(OEt)₂(4), PhP(O)Cl[N(CH₂Ph)₂](5), and {PhP(O)[N(CH₂Ph)₂]}₂O (6). The chloride (5) was not isolated but was characterised by preparation of the derivatives PhP(O)[N(CH₂Ph)₂](NHEt)(11) and PhP(O)[N(CH₂Ph)₂](NHCH₂Ph)(12). PhP(S)Cl₂(2) reacts with dibenzylamine in organic solvents to give PhP(S)Cl[N(CH₂Ph)₂](7), PhP(S)[N(CH₂Ph)₂](OEt)(8), PhP(S)[N(CH₂Ph)₂](NHCH₂Ph)(9), and {PhP(S)[N(CH₂Ph)₂]}₂O (two isomers, 10a and b); and with dibenzylamine in wet benzene to give [NH₂(CH₂Ph)₂]⁺{PhPS[N(CH₂Ph)₂]O}^–(14). The ethoxide derivatives (3, 4, 8) were obtained only in stabilised chloroform. Possible reaction mechanisms are discussed. ¹H N.m.r. spectra of the products provide numerous examples of intrinsically asymmetric methylene groups.