L-(+)-Cysteine → HCID 53800139, compound

109.5 g (0.9 mol) L-cysteine was placed in a 2000 ml flask, and dissolved with 1000 ml water, to which was added 24 ml of 1 mol/l NaOH solution. In an ice bath, 96 ml (1.8 mol) ethylene oxide was slowly added dropwise into the cysteine solution. After stirring 1 h, the ice bath was removed and the mixture was warmed to room temperature and further reacted for 1 h. The reaction product was extracted with 1000 ml anhydrous ethyl ether for four times, while collecting the aqueous layers. The aqueous layers were evaporated to dryness obtaining a yellow crystal product. The yellow crystal product was recrystallized with water:ethanol=85 ml:350 ml, filtered, washed with 2000 ml of 95% ethanol, and dried obtaining 121.8 g of a white crystal product, yield 74.3%.

1. customthe ice bath was removed
2. customfurther reacted for 1 h
3. extractionThe reaction product was extracted with 1000 ml anhydrous ethyl ether for four times
4. customwhile collecting the aqueous layers
5. customThe aqueous layers were evaporated to dryness
6. customobtaining a yellow crystal product
7. customThe yellow crystal product was recrystallized with water
8. filtrationethanol=85 ml:350 ml, filtered
9. washwashed with 2000 ml of 95% ethanol
10. customdried

ORD record

ord-ef4f3088d34e40608c1c099994cb4a89

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08173643B2