Sodium Hydroxide → Foslevodopa

Temperature

25 °C

To a solution of Compound 5, (S)-methyl 2-amino-3-(3-hydroxy-4-(phosphonooxy)phenyl)propanoate, (10.0 g, 34.3 mmol) in 40 mL of water at 15-20° C. was added 22.89 mL (4.0 eq) of 6 N NaOH. When the pH reached 7-8 the solution was passed through a filter for clarification. After clarification, the pH adjustment was continued. After the base was added, the rxn was stirred at 25° C. for 60 mins (pH=12.06). After 60 mins the reaction mixture was acidified with 4.0 eq 6N HCL (137 mmol, 22.89 mL). The final pH was adjusted to 1.8. After 10 mins the rxn mixture became cloudy and 200 mL of IPA was added. The slurry was stirred for 30 mins and the solid was filtered and washed with IPA. The solid was dried in the vacuum oven at 40° C. overnight to afford Compound 6, (S)-2-amino-3-(3-hydroxy-4-(phosphonooxy)phenyl)propanoic acid (7.85 g, 99% purity, 87% yield, 99.6% ee). 1H NMR (400 MHz, Deuterium Oxide) δ 7.24 (dd, J=8.3, 1.3 Hz, 1H), 6.91 (d, J=2.1 Hz, 1H), 6.83 (dd, J=8.3, 2.2 Hz, 1H), 4.25 (dd, J=8.0, 5.2 Hz, 1H), 3.35-3.05 (m, 2H).

1. filtrationa filter for clarification
2. additionAfter the base was added
3. waitAfter 60 mins the reaction mixture was acidified with 4.0 eq 6N HCL (137 mmol, 22.89 mL)
4. waitAfter 10 mins the rxn mixture became cloudy
5. addition200 mL of IPA was added
6. stirringThe slurry was stirred for 30 mins
7. filtrationthe solid was filtered
8. washwashed with IPA
9. customThe solid was dried in the vacuum oven at 40° C. overnight

ORD record

ord-85f7c9fbf1154805949956199bf23097

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09446059B2