Sodium Carbonate → N-Cbz-d-alanine

Under ice cooling, commercially available D-alanine (6.00 g, 73.5 mmol) was dissolved in an aqueous solution (225 mL) of sodium carbonate (21.45 g, 202 mmol), and a dioxane (60 mL) solution of benzyl chloroformate (Z—Cl) (10.5 mL, 73.5 mmol) was slowly added dropwise thereto. After completion of the dropwise addition, the reaction liquid was returned to room temperature, and continuously stirred overnight. The reaction liquid was transferred to a separating funnel, and excess Z—Cl was removed by diethyl ether extraction. Citric acid was added to the aqueous layer to adjust the pH to 3, and then the mixture was extracted three times with ethyl acetate. The combined organic layer was washed once with a saturated saline solution, and the organic layer was dried over anhydrous sodium sulfate, and concentrated under reduced pressure, and then the concentrated residue was recrystallized by ethyl acetate-hexane to obtain a colorless crystal Z-D-alanine (13.77 g, 91.6%).

1. additionAfter completion of the dropwise addition
2. customthe reaction liquid
3. customwas returned to room temperature
4. customcontinuously stirred overnight
5. customThe reaction liquid
6. customwas transferred to a separating funnel
7. customexcess Z—Cl was removed by diethyl ether extraction
8. additionCitric acid was added to the aqueous layer
9. extractionthe mixture was extracted three times with ethyl acetate
10. washThe combined organic layer was washed once with a saturated saline solution
11. dry with materialthe organic layer was dried over anhydrous sodium sulfate
12. concentrationconcentrated under reduced pressure
13. customthe concentrated residue was recrystallized by ethyl acetate-hexane

ORD record

ord-ceb340df11c64519abef2cd0637fe91d

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09422341B2