Réaction #1833239

Équation de réaction

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

Rendement 33.2%

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

Rendement 33.2%

Solvants

ethyl acetate

tetrahydrofuran

Conditions de réaction

Traitement

1. 1
   Températurethe temperature was raised to 40° C.
2. 2
   TempératureThe mixture was cooled to 20° C.
3. 3
   workup.STIRRINGstirred for 3 h
4. 4
   workup.STIRRINGwas stirred for 10 min
5. 5
   LavageThe organic phase was washed with saturated NaCl (10 mL)
6. 6
   Séchagedried (Na2SO4)
7. 7
   Autreevaporated
8. 8
   AutreThe product was purified by flash chromatography with dichloromethane

Mode opératoire

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.

Source