Hydrogen chloride-ethyl acetate → N-[(1S)-2-{[6-(6-ethoxy-1,3-benzoxazol-2-yl)pyridin-3-yl]oxy}-1-methylethyl]acetamide

A mixture of tert-butyl [(1S)-2-{[6-(6-ethoxy-1,3-benzoxazol-2-yl)pyridin-3-yl]oxy}-1-methylethyl]carbamate (5.53 g), 4M hydrogen chloride/ethyl acetate (100 mL) and ethyl acetate (100 mL) was stirred at room temperature for 2 hr. The reaction mixture was concentrated under reduced pressure, and the obtained residue was mixed with acetic anhydride (50 mL) and pyridine (50 mL). The obtained mixture was stirred at room temperature overnight. To the reaction mixture was added 1M hydrochloric acid, and the mixture was extracted with ethyl acetate. The obtained organic layer was washed with saturated brine, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate/methanol), and recrystallized (ethanol/hexane) to give the title compound as white crystals (3.48 g).

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. additionthe obtained residue was mixed with acetic anhydride (50 mL) and pyridine (50 mL)
3. stirringThe obtained mixture was stirred at room temperature overnight
4. additionTo the reaction mixture was added 1M hydrochloric acid
5. extractionthe mixture was extracted with ethyl acetate
6. washThe obtained organic layer was washed with saturated brine
7. dry with materialdried over anhydrous magnesium sulfate
8. customthe solvent was evaporated under reduced pressure
9. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate/methanol)
10. customrecrystallized (ethanol/hexane)

ORD record

ord-e9210b7e1ee54273813b544980856748

Source dataset

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08729102B2