Abstract The reaction of phosphorus trichloride with three p-chloro-substituted diarylamines gave the expected ring-substituted derivatives of the secondary phosphine oxide 1 and the spirophosphonium chloride 2. 4, 4′-Dibromodiphenylamine was converted in part to a tribromo derivative, but 2, 2′, 4, 4′-tetrabromodiphenylamine did not react at all with phosphorus trichloride or tribromide. N-Phenyl-o-toluidine and phosphorus trichloride ...
