Methyl 2-amino-6-fluoro-3-hydroxybenzoate → Methyl 2-amino-5-fluorobenzoxazole-4-carboxylate

To a solution of methyl 2-amino-6-fluoro-3-hydroxybenzoate (0.4 g, 2.2 mmol) in THF (10 mL) was added di-(1H-imidazole-1-yl)methanamine (0.44 g, 2.75 mmol) at room temperature and the resulting reaction mixture was heated at reflux for 16 h. The reaction mixture cooled to room temperature and was concentrated under reduced pressure. The residue was dissolved in CH2Cl2 (100 mL), and the solution was treated with saturated aqueous ammonium chloride (25 mL). The organic layer was separated and the aqueous layer was extracted with additional CH2Cl2 (2×100 mL). The combined organic phase was washed with brine (2×100 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure to afford a yellow solid. The solid was triturated from ether to afford methyl 2-amino-5-fluorobenzoxazole-4-carboxylate. MS consistent.

1. customthe resulting reaction mixture
2. temperaturewas heated
3. temperatureat reflux for 16 h
4. concentrationwas concentrated under reduced pressure
5. dissolutionThe residue was dissolved in CH2Cl2 (100 mL)
6. additionthe solution was treated with saturated aqueous ammonium chloride (25 mL)
7. customThe organic layer was separated
8. extractionthe aqueous layer was extracted with additional CH2Cl2 (2×100 mL)
9. washThe combined organic phase was washed with brine (2×100 mL)
10. dry with materialdried (Na2SO4)
11. filtrationfiltered
12. concentrationconcentrated under reduced pressure
13. customto afford a yellow solid
14. customThe solid was triturated from ether

ORD 기록

ord-eaa3a55acb134139bc55aedf3f9b9501

출처 데이터셋

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US07863271B2