反応 #1833250

反応方程式

Benzo[d][1,3]dioxole

sec-Butyllithium

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

→

title compound

収率 34.5%

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

収率 34.5%

溶媒

tetrahydrofuran

反応条件

後処理

1. 1
   その他the temperature below −100° C
2. 2
   その他the temperature below −100° C
3. 3
   温度to warm to room temperature
4. 4
   その他partitioned between diethyl ether and water
5. 5
   抽出The organic phase was extracted with water once again
6. 6
   抽出The product was extracted with diethyl ether
7. 7
   その他the organic phase was dried
8. 8
   濃縮concentrated under vacuum
9. 9
   その他The product was purified by flash chromatography (silica gel)

実験手順

Benzo[d][1,3]dioxole (3.05 g, 25 mmol) was dissolved in tetrahydrofuran (50 mL) and cooled to −108° C. utilizing a tetrahydrofuran/liquid nitrogen bath. sec-Butyllithium (1.4 M in cyclohexane; 19.64 mL, 27.5 mmol) was added dropwise, keeping the temperature below −100° C. The reaction mixture was then stirred at temperatures between −100° C. and −108° C. for 2 h to ensure complete deprotonation. 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.65 g, 25.00 mmol) was then added to the reaction mixture dropwise, keeping the temperature below −100° C. The reaction mixture was then allowed to warm to room temperature and partitioned between diethyl ether and water. The organic phase was extracted with water once again and the aqueous phases combined and acidified to pH 4 with HCl. The product was extracted with diethyl ether and the organic phase was dried and concentrated under vacuum. The product was purified by flash chromatography (silica gel) to provide the title compound as a white solid (2.14 g, 34.5%): 1H NMR (300 MHz, CDCl3) δ 7.21 (dd, J=7.6, 1.4 Hz, 1H), 6.90 (dd, J=7.7, 1.5 Hz, 1H), 6.82 (t, J=7.6 Hz, 1H), 6.02 (s, 2H), 1.36 (s, 12H); EIMS m/z 248.

出典