1,2-Dibromo-1,1,2,2-tetrachloroethane → 2-Bromo-5-cyclopropyl-3-fluorobenzoic acid

To a solution of TMDA (1.3 ml, 8.61 mmol) in dry THF (9 mL) under inert atmosphere at −65° C., a 1.4M solution of sec-BuLi (8 ml, 11.20 mmol) was added dropwise. Then a solution of 3-cyclopropyl-5-fluorobenzoic acid (0.69 g, 3.83 mmol) in dry THF (3 mL) was added dropwise and stirred for 1 h. Then a solution of 1,2-dibromotetrachloroethane (5 g, 15.48 mmol) in dry THF (11 mL) was added dropwise for 1 h and stirred for additional 20 min. A white suspension was obtained. The cooling bath was removed and at −20° C. water (30 mL) and diethyl ether (30 mL) were added. The organic layer was separated and the aqueous phase was acidified (until pH: 1) using a 2N aqueous solution of HCl (13 mL needed) and extracted with diethyl ether. The organic phase was washed with water and brine, dried, filtered and concentrated in vacuo to afford a mixture 1:1 of the expected compound and starting material (38% yield), which was used without further purification

1. stirringstirred for additional 20 min
2. customA white suspension was obtained
3. customThe cooling bath was removed and at −20° C. water (30 mL) and diethyl ether (30 mL)
4. additionwere added
5. customThe organic layer was separated
6. extractionextracted with diethyl ether
7. washThe organic phase was washed with water and brine
8. customdried
9. filtrationfiltered
10. concentrationconcentrated in vacuo

ORD-Eintrag

ord-17d882e4c5214e0687e66e6964a1161a

Quelldatensatz

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08536165B2