反応 #1833222

反応方程式

5-Bromo-2,2,4-trifluorobenzo[d][1,3]dioxole

isopropylmagnesium chloride lithium chloride

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

→

title compound

収率 72.4%

4,4,5,5-Tetramethyl-2-(2,2,4-trifluorobenzo[d][1,3]dioxol-5-yl)-1,3,2-dioxaborolane

収率 72.4%

溶媒

tetrahydrofuran

NH4Cl

ethyl acetate

反応条件

後処理

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for 1 h at 10-15° C
3. 3
   洗浄The organic phase was washed with saturated NaCl (15 mL)
4. 4
   乾燥dried (Na2SO4)
5. 5
   その他evaporated

実験手順

5-Bromo-2,2,4-trifluorobenzo[d][1,3]dioxole (4.0 g, 16 mmol) was dissolved in 20 mL dry tetrahydrofuran, cooled to −20° C. and treated with isopropylmagnesium chloride-lithium chloride complex (1.3 M in tetrahydrofuran; 13 mL, 17 mmol) in portions over 10 min. After stirring for 30 min at −20 to 0° C., 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.1 g, 17 mmol) was added, and stirring was continued for 1 h at 10-15° C. After treatment with saturated NH4Cl solution (10 mL), the mixture was diluted with ethyl acetate (50 mL). The organic phase was washed with saturated NaCl (15 mL), dried (Na2SO4) and evaporated to give the title compound as a brown solid (3.5 g, 72%): 1H NMR (400 MHz, CDCl3) δ 7.46 (d, J=26.5 Hz, 1H), 6.90 (dd, J=18.5, 4.5 Hz, 1H), 1.35 (s, 12H); 19F NMR (376 MHz, CDCl3) δ −49.70 (s), −126.00 (s); EIMS m/z 302.

出典