N,N,N’,N’-Tetrabromobenzene-1,3-disolfonamide (TBBDS) as an Efficient Promoter for One-Pot Conversion of N-Arylglycines to Sydnones in the Presence of NaNO2/Ac2O under Neutral Conditions

Abstract

N,N,N',N'-Tetrabromobenzene-1,3-disolfonamide (TBBDS)-promoted one-pot conversion of various N-arylglycines to sydnones using a combination of NaNO 2 and Ac 2 O has been achieved efficiently through N-nitrosation followed by cyclization in high yields (85-95%) under mild and neutral conditions.Sydnones (cf.2) are unique members of the class of heterocyclic compounds known as mesoionic. 1Sydnones were first prepared by Earl and Mackney in 1935, 2 and the greatest interest in them, ever since,