Reacción #1833252

Ecuación de reacción

1,2,2-trifluorotrichloroethane

n-Butyllithium

2,2-Difluorobenzo[d][1,3]dioxole

1,2,2-Trifluorotrichloroethane

→

title compound

Rendimiento 74.9%

4-Chloro-2,2-difluorobenzo[d][1,3]dioxole

Rendimiento 74.9%

Disolventes

tetrahydrofuran

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   Otrothe temperature below −70° C
3. 3
   Temperaturacooled to −65° C
4. 4
   workup.ADDITIONto remain between −60° C. and −65° C. during the addition
5. 5
   Temperaturato warm to room temperature
6. 6
   Otropartitioned between diethyl ether and water
7. 7
   ConcentraciónThe organic phase was concentrated

Procedimiento

2,2-Difluorobenzo[d][1,3]dioxole (6.3 g, 39.8 mmol) was dissolved in tetrahydrofuran (66 mL) and cooled to −78° C. n-Butyllithium (2.5 M solution in hexanes; 16.74 mL, 41.8 mmol) was added dropwise, keeping the temperature below −70° C. The reaction mixture was then stirred at −78° C. for 1 h to ensure complete deprotonation. 1,2,2-Trifluorotrichloroethane (14.93 g, 80 mmol) was dissolved in tetrahydrofuran (33 mL) and cooled to −65° C. The lithiate was transferred via cannula into the solution of 1,2,2-trifluorotrichloroethane at a rate that allowed the temperature to remain between −60° C. and −65° C. during the addition. The reaction mixture was then allowed to warm to room temperature and partitioned between diethyl ether and water. The organic phase was concentrated and the product was flashed through 100 g of silica gel using hexane as a solvent to provide the title compound as a clear oil (5.74 g, 74.8%): 1H NMR (400 MHz, CDCl3) δ 7.08 (dd, J=8.2, 1.4 Hz, 1H), 7.03 (t, J=8.0 Hz, 1H), 6.97 (dd, J=7.9, 1.5 Hz, 1H); EIMS m/z 192.

Fuente