A simple method for preparation of N-mono- and N, N-di-alkylated α-amino acids

Abstract

Reactions of α-amino acids with ketones under hydrogenation conditions using 20% Pd(OH) 2/C as the catalyst gave N-mono-alkylated amino acids in high yields. Reductive methylation of N-mono-alkylated amino acids under the same hydrogenation conditions at 50°C afforded N, N-di-alkylated amino acids in excellent yields. This simple method has been used to synthesize N-mono- and N, N-di-alkylated amino acids on a scale of 200 g.