Synthesis of 3,3-disubstituted 2-iminoindolines by cyclization of 1-phenyl-2-acylhydrazines

3,3-Disubstituted 2-iminoindolines and the corresponding 10,10-disubstituted tetrahydropyrimido-1,2-a] indoles, including compounds with spiran structures, were synthesized by reaction of 1-phenyl-2-acylhydrazines and l-phenyl-2-acylpyrazolidines geminally substituted at the-carbon atom of the acyl residue with phosphorus oxychloride. An instance of cleavage of the methyl group was detected.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1632–1635, December, 1975.