Chloroacetyl chloride → (S)-4-benzyl-2,2-dimethyl-5-oxomorpholine-3-carboxylic acid

Temperature

0 °C

To a mixture of (S)-2-(benzylamino)-3-hydroxy-3-methylbutanoic acid (22.86 g, 102.4 mmol), tetrahydrofuran (110 mL), potassium carbonate (42.5 g, 307.2 mmol) and water (70 mL) was added chloroacetyl chloride slowly (17.8 g, 157.7 mmol) at 0° C. over a period of 1 hour, then the mixture was stirred at 0° C. for 3 hours. To the reaction mixture was added a solution of sodium hydroxide (16.4 g, 409.6 mmol) in water (40 mL) over a period of 1 hour. At the end of addition, the mixture was cooled to 3° C.-5° C., and the mixture was stirred at the temperature for 4 hours. Then the reaction mixture was warmed to room temperature, and washed with Petroleum ether (50 mL×2). The aqueous layer was cooled to 3° C. below and adjusted to pH 2 with con. HCl. The mixture was stirred at 6° C. below for 12 hours, then filtered. The filter cake was washed with water to give the title compound as a white solid (18.6 g, 69%). The compound was characterized by the following spectroscopic data:

1. additionAt the end of addition
2. temperaturethe mixture was cooled to 3° C.-5° C.
3. stirringthe mixture was stirred at the temperature for 4 hours
4. temperatureThen the reaction mixture was warmed to room temperature
5. washwashed with Petroleum ether (50 mL×2)
6. temperatureThe aqueous layer was cooled to 3° C. below and
7. stirringThe mixture was stirred at 6° C. below for 12 hours
8. filtrationfiltered
9. washThe filter cake was washed with water

ORD record

ord-58ca3f809e794a1db804f19986e8cae3

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09340538B2