反応 #1833251

反応方程式

2,2-Difluorobenzo[d][1,3]dioxole

sec-Butyllithium

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

→

title compound

収率 65.5%

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

収率 65.5%

溶媒

tetrahydrofuran

反応条件

後処理

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   その他the temperature below −65° C
3. 3
   その他the temperature below −65° C
4. 4
   温度to warm to room temperature
5. 5
   workup.WAITsit at room temperature for 2 h
6. 6
   その他was then partitioned between diethyl ether and water
7. 7
   抽出The product was extracted with diethyl ether
8. 8
   その他the organic phase was dried
9. 9
   濃縮concentrated under vacuum

実験手順

2,2-Difluorobenzo[d][1,3]dioxole (6 g, 38.0 mmol) was dissolved in tetrahydrofuran (100 mL) and cooled to −75° C. sec-Butyllithium (1.4 M in cyclohexane; 29.8 mL, 41.7 mmol) was added dropwise, keeping the temperature below −65° C. The reaction mixture was then stirred at −75° C. for 1 h to ensure complete deprotonation. 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (7.06 g, 38.0 mmol) was then added to the reaction mixture dropwise keeping the temperature below −65° C. The reaction mixture was then allowed to warm to room temperature and sit at room temperature for 2 h and was then partitioned between diethyl ether and water. The aqueous phase was acidified to pH 3 with 12 N HCl. The product was extracted with diethyl ether and the organic phase was dried and concentrated under vacuum to provide the title compound as an off-white solid (7.06 g, 65.5%): 1H NMR (300 MHz, CDCl3) δ 7.43 (dd, J=7.5, 1.5 Hz, 1H), 7.13 (dd, J=7.9, 1.5 Hz, 1H), 7.05 (t, J=7.7 Hz, 1H), 1.37 (s, 12H); EIMS m/z 284.

出典