DIARYLPHOSPHINIC AZIDES. PHOTOCHEMICAL REACTIONS INCLUDING REARRANGEMENT IN METHANOL

Article abstract of DOI:10.1016/0040-4020(82)80240-8

On photolysis in methanol the diarylphosphinic azides Ar2P(O)N3 (Ar=phenyl, p-tolyl, p-anisyl, p-chlorophenyl) rearrange with loss of nitrogen to form (monomeric) metaphosphonimidates which are trapped by the solvent to give methyl NP-diarylphosphonamidates (7) (41-53percent).Diarylphosphinic amides (18-42percent) are also usually formed, presumably from (triplet) nitrenes.The limited evidence available suggests that the rearrangements take place directly from the photo-excited azides rather than via (singlet) nitrene intermediates.One of the products of rearrangement, methyl NP-di(p-chlorophenyl)phosphonamidate, suffers extensive photochemical dechlorination giving methyl N-phenyl-P-p-chlorophenylphosphonamidate.