反応 #1833239

反応方程式

NH4Cl

6-Bromo-4-methoxybenzo[d][1,3]dioxole

isopropylmagnesium lithium chloride

HCl

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

→

title compound

収率 33.2%

2-(7-Methoxybenzo[d][1,3]dioxol-5-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

収率 33.2%

溶媒

ethyl acetate

tetrahydrofuran

反応条件

後処理

1. 1
   温度the temperature was raised to 40° C.
2. 2
   温度The mixture was cooled to 20° C.
3. 3
   workup.STIRRINGstirred for 3 h
4. 4
   workup.STIRRINGwas stirred for 10 min
5. 5
   洗浄The organic phase was washed with saturated NaCl (10 mL)
6. 6
   乾燥dried (Na2SO4)
7. 7
   その他evaporated
8. 8
   その他The product was purified by flash chromatography with dichloromethane

実験手順

6-Bromo-4-methoxybenzo[d][1,3]dioxole (1.5 g, 6.5 mmol, prepared according to Shirasaka, Tadashi; Takuma, Yuki; Imaki, Naoshi. Synthetic Communications 1990, 20, 1223-1232) was dissolved in dry tetrahydrofuran (25 mL), cooled to 5° C. and treated with isopropylmagnesium lithium chloride (1.3 M; 5.2 mL, 6.8 mmol). After 50 min at 10° C., the temperature was raised to 40° C. and stirred for 5 h. The mixture was cooled to 20° C., treated with 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.3 g, 7.1 mmol) and stirred for 3 h. The mixture was treated with saturated NH4Cl (2 mL), followed by 1 M HCl (8 mL) and ethyl acetate (20 mL), and then was stirred for 10 min. The organic phase was washed with saturated NaCl (10 mL), dried (Na2SO4) and evaporated. The product was purified by flash chromatography with dichloromethane to give the title compound as a white solid (600 mg; 33%): mp 86-88° C.; 1H NMR (400 MHz, CDCl3) δ 7.01 (d, J=0.5 Hz, 1H), 6.97 (d, J=0.8 Hz, 1H), 5.98 (s, 2H), 3.93 (s, 4H), 1.33 (s, 12H); EIMS m/z 278.

出典