反応 #1833232

反応方程式

NH4Cl

5-Bromo-2-methylbenzo[d][1,3]dioxole

n-BuLi

NaCl

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

→

title compound

収率 59.3%

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

収率 59.3%

溶媒

tetrahydrofuran

ethyl acetate

反応条件

後処理

1. 1
   乾燥dried (Na2SO4)
2. 2
   その他evaporated
3. 3
   その他The material was purified by chromatography on silica with a 0-30% ethyl acetate-hexane gradient

実験手順

5-Bromo-2-methylbenzo[d][1,3]dioxole (1.0 g, 4.7 mmol, prepared as described in Matyus, Peter; Magyar, Kalman; Pihlavista, Marjo; Gyires, Klara; Haider, Norbert; Wang, Yinghua; Woda, Patrick; Dunkel, Petra; Toth-Sarudy, Eva; Turos, Gyoergy, WO2010029379) was dissolved in dry tetrahydrofuran (10 mL), cooled to −70° C. and treated with n-BuLi (2.5 M; 2.1 mL, 4.7 mmol) over 5 min. After 1 h, 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.1 g, 6.0 mmol) was added and the mixture was stirred for 90 min at −70 to −30° C. After addition of saturated NH4Cl (5 mL), the mixture was shaken with ethyl acetate (40 mL) and saturated NaCl (10 mL), dried (Na2SO4) and evaporated. The material was purified by chromatography on silica with a 0-30% ethyl acetate-hexane gradient to give the title compound (730 mg, 59%): 1H NMR (400 MHz, CDCl3) δ 7.33 (dd, J=7.7, 1.1 Hz, 1H), 7.18 (d, J=0.9 Hz, 1H), 6.77 (d, J=7.8 Hz, 1H), 6.25 (q, J=5.0 Hz, 1H), 1.66 (d, J=4.9 Hz, 3H), 1.32 (s, 12H); EIMS m/z 262.

出典