Reaction #1833245

Reaction equation

NH4Cl

(2,2-Difluorobenzo[d][1,3]dioxol-4-yl)trimethylsilane

sec-BuLi

HCl

2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

→

title compound

(2,2-Difluoro-7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[d][1,3]dioxol-4-yl)trimethylsilane

Solvents

water

tetrahydrofuran

Conditions

Workup

1. 1
   Temperaturewarmed to 20° C
2. 2
   Extractionextracted with diethyl ether (100 mL)
3. 3
   WashThe organic phase was washed with saturated NaCl (15 mL)
4. 4
   Dryingdried (Na2SO4)
5. 5
   Otherevaporated

Procedure

(2,2-Difluorobenzo[d][1,3]dioxol-4-yl)trimethylsilane (5.0 g, 22 mmol, prepared as described in Gorecka, Joanna; Leroux, Frederic; Schlosser, Manfred, European Journal of Organic Chemistry 2004, 1, 64-68) was added to a stirred solution of sec-BuLi (1.4 M; 10 mL, 14 mmol) in dry tetrahydrofuran (28 mL) cooled to −75° C. After 2 h at −75° C., 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.2 g, 23 mmol) was added, and the mixture was stirred for 90 min at −75° C. The mixture was treated with saturated NH4Cl (5 mL) and warmed to 20° C. The mixture was combined with water (75 mL), acidified with 6 M HCl and extracted with diethyl ether (100 mL). The organic phase was washed with saturated NaCl (15 mL), dried (Na2SO4) and evaporated to give the title compound (estimated purity of 60%) which was used without further purification: 1H NMR (400 MHz, CDCl3) δ 7.39 (d, J=7.5 Hz, 1H), 7.07 (d, J=7.5 Hz, 1H), 1.36 (s, 12H), 0.33 (s, 9H); 19F NMR (376 MHz, CDCl3) δ −49.33; EIMS m/z 356.

Source