Hydrochloric Acid → Arbaclofen Hydrochloride

Temperature

100 °C

Under a nitrogen atmosphere, methyl (3S,4R)-4-(4-chlorophenyl)-2-oxopyrrolidine-3-carboxylate (5.00 g, 19.7 mmol) was suspended in 1,2-dichlorobenzene (25 ml), and the suspension was dropped over a period of about 3 hours into 6 mol/L hydrochloric acid (20 g) heated up to 100° C. The mixture was reacted for 10 hours, then, cooled to 80° C., and the organic layer was separated by a liquid-separation operation. The aqueous layer was concentrated under reduced pressure, acetonitrile (15 ml) was added, and the mixture was concentrated again, then, acetonitrile (30 ml) was added, and the mixture was stirred at room temperature for 1 hour. The crystal was filtrated and washed with acetonitrile (5 ml) to obtain 4.00 g (16.0 mmol) of a title compound (yield: 81%). The spectrum data corresponded to the value in Example 4. The optical purity of the resultant title compound was measured by HPLC to find a value of 99.9% ee.

1. customThe mixture was reacted for 10 hours
2. temperaturecooled to 80° C.
3. customthe organic layer was separated by a liquid-separation operation
4. concentrationThe aqueous layer was concentrated under reduced pressure, acetonitrile (15 ml)
5. additionwas added
6. concentrationthe mixture was concentrated again
7. additionacetonitrile (30 ml) was added
8. filtrationThe crystal was filtrated
9. washwashed with acetonitrile (5 ml)

ORD record

ord-0829439d1af348c285c9d88e9aa8a03e

Source dataset

uspto-grants-2012_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08293926B2