Methyl chloroformate → Nalpha-methoxycarbonyl-DL-methionine amide

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.

1. additionwas 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. customAfter drying in a vacuum, 162 g yellowish
9. dissolutionIt was dissolved in 200 ml hot ethanol
10. additionThen, 400 ml MTBE was added
11. temperatureAfter cooling in an ice bath
12. filtrationfiltering off
13. washwashing with 200 ml MTBE
14. customdrying

ORD record

ord-7dd267102c25483d9307fdc0a30a3531

Source dataset

uspto-grants-2001_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06333176B1