Phosphorylation of diarylamines

Phosphorylation of N-methyldiphenylamine and N-methyl-N-phenylnaphthylamine s with phosphorus tribromide in basic medium occurs at the benzene ring wit h formation of the corresponding p-dihromophosphino derivatives. The lone e lectron pair on the nitrogen atom in N-methyl-N-phenylnaphthylamines is not conjugated with the naphthalene ring. Reactions of N-methyldiphenylamine a nd N-methyl-N-phenyl-alpha-naphthylamines with excess phosphorus tribromide give rise to bis(dinromophosphino) derivatives.