Hydrochloric Acid → methyl (3S)-3-amino-2-hydroxybutanoate

Into a suspension of (3S)-3-amino-2-hydroxybutanoic acid (1.0 g, 8.4 mmol) in methanol (25 ml) was bubbled anhydrous hydrogen chloride gas until a solution resulted. After a solution resulted, the reaction was cooled in an ice bath and saturated with hydrogen chloride. The cooling bath was removed and the reaction stirred at room temperature for 3.5 hours. The solvent was removed on a rotary evaporator at ambient temperature and the resultant residue dissolved in methanol (25 ml), cooled in an ice bath and saturated with hydrogen chloride gas. Warming of the reaction solution to room temperature and removal of the solvent on a rotary evaporator gave an oil. To this oil was added triethylamine (15 ml) followed by the minimum amount of methanol (about 15 ml) needed to dissolve the initial gummy solid. The solution was cooled in an ice bath and ether (75 ml) added in portions with stirring. The precipitated triethylamine hydrochloride was filtered and the filtrate evaporated to give methyl (3S)-3-amino-2-hydroxybutanoate.

1. customwas bubbled anhydrous hydrogen chloride gas until a solution
2. customresulted
3. customAfter a solution resulted
4. customThe cooling bath was removed
5. customThe solvent was removed on a rotary evaporator at ambient temperature
6. dissolutionthe resultant residue dissolved in methanol (25 ml)
7. temperaturecooled in an ice bath and saturated with hydrogen chloride gas
8. temperatureWarming of the reaction solution to room temperature
9. customremoval of the solvent
10. customon a rotary evaporator
11. customgave an oil
12. dissolutionto dissolve the initial gummy solid
13. temperatureThe solution was cooled in an ice bath
14. stirringwith stirring
15. filtrationThe precipitated triethylamine hydrochloride was filtered
16. customthe filtrate evaporated

ORD record

ord-7925d5951dce48a8ad5c3750aa84a9be

Source dataset

uspto-grants-2000_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06130315