Methyl chloroformate → Nalpha-methoxycarbonyl-DL-methionine amide

Participants

Reaction Steps

85 ml (1.11 moles) methylchloroformate were dripped into a solution of 150 g (1.02 moles) DL-methionine amide in 200 ml water at 5-10° C., during which the pH was maintained at 8-10 by the addition of sodium hydroxide solution. After 30 min of subsequent reaction, 60 ml water was added, whereupon crystals formed which were filtered off, washed with water and dissolved in 250 ml water. This solution was extracted twice and the crystallization mother liquor extracted once with 500 ml methylene chloride in each instance. After drying in a vacuum, 162 g yellowish, crystalline residue remained. It was dissolved in 200 ml hot ethanol. Then, 400 ml MTBE was added and after the appearance of the first colorless crystals another 200 ml MTBE. After cooling in an ice bath, filtering off, washing with 200 ml MTBE and drying, 127 g (60k) Nα-methoxycarbonyl-DL-methionine amide with a melting point of 93-94° C. was obtained.

Provenance & Evidence