Ammonia → HCID 11052302, compound

A mixture of 5 g of racemic ethyl 2-(4-chlorophenyl)-propionate and 50 ml of tert-butanol is treated at 50° C. with stirring with 1 g of lipase from Candida antarctica (Novozym 435, activity 7000 PLU/g). Ammonia is then passed into the reaction mixture with stirring at 50° C. until it is saturated. The mixture is stirred at 50° C. for a further 28 hours and during the course of this a slow stream of ammonia is continuously passed through the apparatus. The mixture is then worked up by filtering off the biocatalyst, washing it with tert-butanol and ethanol, concentrating the filtrate under reduced pressure and stirring the residue which remains with a mixture of petroleum ether:di-isopropyl ether=9:1. The product obtained in crystalline form is filtered off, washed with petroleum ether and dried. In this manner 1.78 g (42.8% of theory, conversion 44 area per cent GC) of (R)-2-(4-chloro-phenyl)-propionamide having an ee value of 96.1% are obtained.

1. additionis treated at 50° C.
2. stirringwith stirring at 50° C. until it
3. filtrationby filtering off the biocatalyst
4. washwashing it with tert-butanol and ethanol
5. concentrationconcentrating the filtrate under reduced pressure
6. stirringstirring the residue which
7. additionremains with a mixture of petroleum ether
8. customThe product obtained in crystalline form
9. filtrationis filtered off
10. washwashed with petroleum ether
11. customdried

ORD record

ord-32dda11231a9400dacd19b3d0d1ada2f

Source dataset

uspto-grants-1998_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05773656