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.