1,1-Dibromo-1,2,2,2-tetrafluoroethane → 2-Bromo-4-(trifluoromethoxy)cyclopropoxybenzene

4-(Trifluoromethoxy)cyclopropoxybenzene (3 g) was dissolved in tetrahydrofuran (100 ml) and the solution was cooled to −78° C. under a nitrogen atmosphere. tert-Butyllithium (22.9 ml, 1.5M in pentane) was added dropwise and the solution was stirred for 3 hours. Dibromotetrafluoroethane (8.2 ml) was added dropwise and the reaction mixture was stirred at −78° C. for 2 hours. The reaction was quenched by the dropwise addition of water (50 ml). The product was extracted with diethyl ether. The combined organic fractions were dried (brine, MgSO4) and concentrated in vacuo. The residue was purified on silica using hexane as eluant, to yield the product as a colourless oil (2.2 g). 1H NMR (360 MHz, CDCl3) δ 0.86 (4H, m), 3.79 (1H, m), 7.15 (1H, dd, J 8.9, 2.7 Hz), 7.24 (1H, d, J 8.9 Hz), 7.42 (1H, d, J 2.7 Hz).

1. stirringthe reaction mixture was stirred at −78° C. for 2 hours
2. customThe reaction was quenched by the dropwise addition of water (50 ml)
3. extractionThe product was extracted with diethyl ether
4. dry with materialThe combined organic fractions were dried (brine, MgSO4)
5. concentrationconcentrated in vacuo
6. customThe residue was purified on silica

ORD-Eintrag

ord-dc9c001e9df94fe4bd7e7d5fdbbc9ee2

Quelldatensatz

uspto-grants-2002_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06372754B1