Selective N-nitrosation of amines, N-alkylamides and N-alkylureas by N2O4 supported on cross-linked polyvinylpyrrolidone (PVP-N2O4)

N2O4 was supported on the cross-linked polyvinylpyrrolidone (PVP) to afford a solid, stable and recyclable nitrosating agent. This reagent shows excellent selectivity for N-nitrosation of dialkyl amines in the presence of diaryl-, arylalkyl-, trialkylamines and also for secondary amides in dichloromethane at room temperature under mild and heterogeneous conditions. Also N-nitroso-N-alkyl amides can be selectively prepared in the presence of primary amides and N-phenylamides under similar reaction conditions. Selective N-nitrosation or dealkylation and N-nitrosation of tertiary amines can also be performed by this reagent.