Ilia R= CH2C6H5 b R= CH2CHS found that the indolenine Ilia was formed directly without a catalyst and that Ilia then immediately added Phenylhydrazine to form the addition compound IIa. The C= N group adds not only amines, ammonia and Phenylhydrazine, but also acid anhydrides (acetic, benzoic and phthalic anhydride) to give the indoline derivatives which have the general formula of IV.