反应详情

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 were 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 rotating in, 162 g yellowish, crystalline residue remained. It was dissolved in 200 ml hot ethanol. Then, 400 ml MTBE were 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 (60%) Nα -methoxycarbonyl-DL-methionine amide with a melting point of 93-94° C. were obtained.

1. additionwere added, whereupon crystals
2. customformed which
3. filtrationwere filtered off
4. washwashed with water
5. dissolutiondissolved in 250 ml water
6. extractionThis solution was extracted twice
7. extractionthe crystallization mother liquor extracted once with 500 ml methylene chloride in each instance
8. dissolutionIt was dissolved in 200 ml hot ethanol
9. additionThen, 400 ml MTBE were added
10. temperatureAfter cooling in an ice bath
11. filtrationfiltering off
12. washwashing with 200 ml MTBE
13. customdrying