Ethyl chloroformate → Ethyl 3-bromo-5-fluoropyridine-4-carboxylate

To a −78° C. solution of LDA (2 M solution in heptane/THF, 14.2 mL, 28.4 mmol) in anhydrous THF (45 mL) was added a solution of the 3-bromo-5-fluoropyridine (5.0 g, 28.4 mmol) in anhydrous THF (20 mL). The reaction mixture was stirred at −78° C. for 45 minutes. Then, a solution of ethyl chloroformate (24 mL, 284 mmol) was added slowly over 10 minutes. After stirring for 20 minutes, the reaction mixture was quenched with a saturated solution of NaHCO3. The mixture was extracted into ethyl acetate (3×100 mL). The combined organic extracts were extracted with water (2×200 mL), dried over MgSO4, filtered, evaporated, and dried in vacuo, affording ethyl 3-bromo-5-fluoropyridine-4-carboxylate (4.8 g, 69% yield). The product was used without further purification.

1. stirringAfter stirring for 20 minutes
2. customthe reaction mixture was quenched with a saturated solution of NaHCO3
3. extractionThe mixture was extracted into ethyl acetate (3×100 mL)
4. extractionThe combined organic extracts were extracted with water (2×200 mL)
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. customevaporated
8. customdried in vacuo

ORD 기록

ord-fc9e11f9d98f40238b35bb4c86fb9a9f

출처 데이터셋

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US09040538B2