The Staudinger reaction of several ortho-substituted arylazides with triphenylphosphine has been studied. The reaction product is found to be strongly dependent on the nature of the ortho-substituent. The Aza Wittig-type reaction of iminophosphorane derived from the ortho-azido acetophenone with isocyanates and aroyl chlorides leads to the previously unreported 4-methylene-4H-3,1-benzoxazine ring. The crystal and molecular structure of 2-[2-(4-methoxybenzoylamino)phenyl]-4-methylquinoline has been established by X-Ray diffraction methods.