N-alkylation of imides using phase transfer catalysts under solvent-free conditions

N-Alkylation of imides in the reaction of imides and alkylhalides, catalyzed by PT catalysts under solvent-free conditions, has been developed. The reaction occurs in the presence of K2CO3, and in many cases it takes place spontaneously. In the N-benzylation reaction, it has been recognized that TBAB (tetrabutylammonium bromide) and TBATFB (tetrabutylammonium tetrafluoroborate) show highest catalytic effect. Versatility and synthetic capacity of the solvent-free alkylation has been confirmed by N-benzylation and N-ethylation of various imides. The developed procedure gives easy access to N-(omega-bromoalkyl)imides.