Acetic Anhydride → HCID 66672660, compound

(2R)-2-Amino-2-methyl-4-(1-methylpyrrol-2-yl)butan-1-ol 1/2 D-(−)-tartrate (3.98 g, 15.5 mmol) obtained in Reference example 1 (1 g) was suspended in a mixture of methylene chloride (50 mL) and water (12.5 mL) and an aqueous sodium hydroxide solution (3.20 g of 97% sodium hydroxide was dissolved in 12.5 mL of water) was added thereto, followed by stirring of the mixture at room temperature for 20 minutes. Methylene chloride was added to the reaction mixture to separate it. The thus obtained organic phase was separated and dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under reduced pressure and the residue was dissolved in methylene chloride (78 mL). Triethylamine (21.5 mL, 155 mmol), acetic anhydride (7.30 mL, 77.4 mmol) and 4-dimethylaminopyridine (0.189 g, 1.55 mmol) were added thereto and the mixture was stirred at room temperature for 1 hour. Methanol was added thereto to stop the reaction and the solvent was evaporated under reduced pressure. Ethyl acetate and water were added to the residue to separate it. The thus obtained organic phase was separated, washed with water, a saturated aqueous sodium hydrogencarbonate solution and a saturated aqueous NaCl solution and dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under reduced pressure and the residue was purified by silica gel chromatography (ethyl acetate) to obtain the title compound (4.23 g, yield: quantitative).

1. customto separate it
2. customThe thus obtained organic phase was separated
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationAfter filtration
5. customthe solvent was evaporated under reduced pressure
6. dissolutionthe residue was dissolved in methylene chloride (78 mL)
7. stirringthe mixture was stirred at room temperature for 1 hour
8. customthe reaction
9. customthe solvent was evaporated under reduced pressure
10. additionEthyl acetate and water were added to the residue
11. customto separate it
12. customThe thus obtained organic phase was separated
13. washwashed with water
14. dry with materiala saturated aqueous sodium hydrogencarbonate solution and a saturated aqueous NaCl solution and dried over anhydrous sodium sulfate
15. filtrationAfter filtration
16. customthe solvent was evaporated under reduced pressure
17. customthe residue was purified by silica gel chromatography (ethyl acetate)

ORD record

ord-903abdcb1f314551a65e3ff2fb920f7f

Source dataset

uspto-grants-2011_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07910617B2