Reaction #1833232

Reaction equation

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

Yield 59.3%

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

Yield 59.3%

Solvents

tetrahydrofuran

ethyl acetate

Conditions

Workup

1. 1
   Dryingdried (Na2SO4)
2. 2
   Otherevaporated
3. 3
   OtherThe material was purified by chromatography on silica with a 0-30% ethyl acetate-hexane gradient

Procedure

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.

Source