Syntheses of methylcarbamoylated amino acids using synthetic equivalents of methyl isocyanate

A simple environmentally friendly one-step synthetic procedure was developed for S- and N-methylcarbamoylation of amino acids their derivatives in buffered aqueous solutions. N-Succinimidyl N-methylcarbamate (SNMC) N,S-dimethylthiocarbamate (DMTC) were used as equivalents to replace highly hazardous methyl isocyanate (MIC). SNMC reacted rapidly both N-methylcarbamoylations affording nearly quantitative conversions (>97 %) all tested compounds after 2–3 h at 50 °C pH 8.2 9.5–10 N-methylcarbamoylations, respectively. Under the same conditions, DMTC more slowly (48 N-methylcarbamoylations) but with some polar it provided products higher purity than SNMC. Similarly, N-trideuteriomethyl-S-methylthiocarbamate (DMTC-d3) synthesize Nα- Nε-trideuteriomethylcarbamoyl valine lysine, Prepared will be toxicological research authentic standards analyses protein adducts derived from MIC or its metabolic precursor, N,N-dimethylformamide.