A facile rearrangement of N-alkyl, N-(0 or p-nitrophenylsulfonamide)-α-amino esters

The N-alkylation of primary nitrophenylsulfonamides followed by removal of the nitrophenylsulfonamide moiety under nucleophilic conditions to provide secondary amines has become an established literature procedure. Application of this methodology with less reactive alkylating agents can give rise to side products resulting from a nitrogen to carbon transfer of the nitrophenyl ring. This side product predominates when tetrabutylammonium hydroxide is used in place of metal carbonate bases in the N-alkylation step.