反応 #1833249

反応方程式

5-bromo-2,2-difluorobenzo[d][1,3]dioxole

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

→

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

収率 84.4%

溶媒

tetrahydrofuran

反応条件

後処理

1. 1
   workup.ADDITIONIsopropylmagnesium chloride-lithium chloride complex (1.3 M; 10 mL, 13.0 mmol) was added slowly
2. 2
   workup.STIRRINGthe reaction mixture was stirred for 1 h
3. 3
   その他The reaction was quenched with saturated aqueous ammonium chloride
4. 4
   抽出extracted three times with ethyl acetate
5. 5
   洗浄The combined organic layers were washed with brine
6. 6
   乾燥dried over anhydrous magnesium sulfate
7. 7
   ろ過The solution was filtered
8. 8
   濃縮concentrated

実験手順

To an oven-dried three-necked round bottom flask under nitrogen was added 5-bromo-2,2-difluorobenzo[d][1,3]dioxole (2.516 g, 10.6 mmol) and anhydrous tetrahydrofuran (26 mL). The solution was cooled to 0° C. Isopropylmagnesium chloride-lithium chloride complex (1.3 M; 10 mL, 13.0 mmol) was added slowly and stirred for 1 h. 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.2 mL, 10.62 mmol) was added, and the reaction mixture was stirred for 1 h. The reaction was quenched with saturated aqueous ammonium chloride and extracted three times with ethyl acetate. The combined organic layers were washed with brine and dried over anhydrous magnesium sulfate. The solution was filtered and concentrated to provide 2-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane as a yellow oil (2.54 g, 84%): 1H NMR (400 MHz, CDCl3) δ 7.56 (dd, J=8.0, 1.0 Hz, 1H), 7.47 (d, J=0.6 Hz, 1H), 7.06 (dd, J=7.9, 0.4 Hz, 1H), 1.34 (s, 12H); 19F NMR (376 MHz, CDCl3) δ −50.18; EIMS m/z 284.

出典