Synthesis of Cyclic Azomethine Imines from Aza β-Lactams. Conversion of 3-Oxo-1,2-diazetidinium Tosylates into 1-Substituted 3-Oxo-1,2-diazetidinium Inner Salts

Article abstract of DOI:10.1021/jo00172a025

Dehydrohalogenation of (α-haloacyl)hydrazones of benzophenone gives 1-(diphenylmethylene)-3-oxo-1,2-diazetidinium inner salts (2,5,6), which are hydrolyzed with 1 molar equiv of p-toluenesulfonic acid monohydrate in CH2Cl2 to give 3-oxo-1,2-diazetidinium