Dl-Phenylalanine → HCID 54501347, compound

33g (0.20 mol) of DL-phenylalanine was neutralized with 100 ml of 2N-NaOH solution and to the resulting solution were simultaneously added dropwise 34.2g (0.20 mol) of 2-bromo-propionylchloride and 110 ml of 2N-NaOH solution over about one hour while stirring and ice-cooling. During the reaction, the reaction mixture was maintained in a slightly alkaline condition. After completion of the addition, the ice-bath was removed and the mixture was stirred at room temperature for a further 2 hours. The filtrate which had been prepared by neutralizing 33.7g (0.24 mol) of thiobenzoic acid with 122 ml of 2N--KOH solution and filtering the thus obtained solution was added to the reaction mixture. The mixture was stirred at room temperature overnight and then acidified with hydrochloric acid while ice-cooling to form oil. The oil was extracted with ethyl acetate and the extract was washed with water, dried over anhydrous sodium sulfate, and then allowed to be placed under reduced pressure to remove the ethyl acetate. During removal of the ethyl acetate, crystals started to precipitate. After completion of the evaportion, benzene was added to these crystals and they were recovered by filtration and washed with benzene to give 25.0g of N-(2-benzoylmercaptopropionyl)phenylalanine. (m.p. 173° - 175°C)

1. temperatureice-cooling
2. customDuring the reaction
3. temperaturethe reaction mixture was maintained in a slightly alkaline condition
4. additionAfter completion of the addition
5. customthe ice-bath was removed
6. stirringthe mixture was stirred at room temperature for a further 2 hours
7. filtrationKOH solution and filtering the thus obtained solution
8. additionwas added to the reaction mixture
9. stirringThe mixture was stirred at room temperature overnight
10. temperaturecooling
11. customto form oil
12. extractionThe oil was extracted with ethyl acetate
13. washthe extract was washed with water
14. dry with materialdried over anhydrous sodium sulfate
15. customto remove the ethyl acetate
16. customDuring removal of the ethyl acetate, crystals
17. customto precipitate
18. additionAfter completion of the evaportion, benzene was added to these crystals and they
19. filtrationwere recovered by filtration
20. washwashed with benzene

ORD record

ord-79c3fb1205f942c6a7098e3e23326e44

Source dataset

uspto-grants-1976_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03971828