Methylenation of the nitrogen–halogen bond of positive halogen compounds

Abstract

The N–X bond of positive halogen compounds (I) can be readily methylenated at 15° with diazomethane to give the N-halogenomethyl derivatives (III), not isolated as such but directly condensed with nucleophiles [sodium p-nitrophenoxide, diethyl phthalimido(sodio)malonate, and morpholine]; the parent N–H compounds (VII) are formed as secondary products. This new reaction has been applied to N-halogeno-N-substituted carboxamides, sulphonamides, phosphoramides, and urethanes. The mechanism of the methylene insertion into the N–X linkage is discussed.