Simple and Efficient Microwave Assisted N-Alkylation of Isatin

Abstract

We present herein the results of microwave promoted N-alkylations of isatin ( 1) with different alkyl, benzyl and functionalized alkyl halides. Reactions were carried out under different conditions, always employing methodologies compatible with MW assisted chemistry. Generation of isatin anion employing diverse bases and solvents or using the preformed isatin sodium salt was tested. The best results were achieved using K ₂CO ₃ or Cs ₂CO ₃ and a few drops of N,N-dimethylformamide or N-methyl-2-pyrrolidinone. These reactions present noteworthy advantages over those carried out employing conventional heating.