L-Methionine → methyl (2S)-2-amino-4-(methylsulfanyl)butanoate

Temperature

0 °C

At about 0° C., acetyl chloride (15 mL) was added dropwise to methanol (100 mL). After stirring for about 10 minutes at about 0° C., L-methionine (8.5 g, 57 mmol) was added and the resulting solution was stirred for about 10 minutes. The solution was then heated at reflux for about 4 hours, and then maintained at ambient temperature for about 16 hours. The solvent was removed in vacuo, the resulting residue was dissolved in chloroform (100 mL), and the solution was neutralized to pH 7-8 by the careful addition of a saturated aqueous sodium bicarbonate solution. Following standard extractive workup with chloroform, the resulting residue was kept under high vacuum for about two hours to afford the title product as a colourless oily liquid, which was used directly in the next step without any further purification (crude yield 6 g, 65%).

1. stirringthe resulting solution was stirred for about 10 minutes
2. temperatureThe solution was then heated
3. temperatureat reflux for about 4 hours
4. temperaturemaintained at ambient temperature for about 16 hours
5. customThe solvent was removed in vacuo
6. dissolutionthe resulting residue was dissolved in chloroform (100 mL)
7. additionthe solution was neutralized to pH 7-8 by the careful addition of a saturated aqueous sodium bicarbonate solution
8. waitthe resulting residue was kept under high vacuum for about two hours

ORD record

ord-4e939417f46d44a78ab7ccf1782ddaee

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07767860B2