反応 #1899361

反応方程式

lithium diisopropylamide

heptane tetrahydrofuran ethylbenzene

6-fluoro-2-(2-methoxyethoxy)-pyridin-3-ylboronic acid

triisopropyl borate

2-Fluoro-6-(2-methoxyethoxy)pyridine

→

2-fluoro-6-(2-methoxyethoxy)pyridin-3-ylboronic acid

収率 15.9%

溶媒

THF

反応条件

後処理

1. 1
   温度to warm to RT over 30 min
2. 2
   その他It was then quenched by the addition of a saturated solution of ammonium chloride
3. 3
   workup.STIRRINGstirred for 30 min
4. 4
   抽出The reaction mixture was extracted with EtOAc (3×25 mL)
5. 5
   乾燥dried over MgSO4
6. 6
   ろ過filtered
7. 7
   濃縮concentrated
8. 8
   その他Purification on the ISCO (12 g column, 5-100% EtOAc)
9. 9
   その他gave

実験手順

2-Fluoro-6-(2-methoxyethoxy)pyridine (1.13 g, 6.60 mmol) in THF (5 mL) was cooled to −60° C. and treated with lithium diisopropylamide, 2.0 M solution in heptane/tetrahydrofuran/ethylbenzene (4.95 mL, 9.90 mmol) (Aldrich) and stirred at −60° C. for 1 h. The mixture was then treated with triisopropyl borate (2.277 mL, 9.90 mmol) (Aldrich) and allowed to warm to RT over 30 min. It was then quenched by the addition of a saturated solution of ammonium chloride and stirred for 30 min. The reaction mixture was extracted with EtOAc (3×25 mL), dried over MgSO4, filtered and concentrated. Purification on the ISCO (12 g column, 5-100% EtOAc) gave a mixture of 2-fluoro-6-(2-methoxyethoxy)pyridin-3-ylboronic acid (226 mg, 1.051 mmol, 15.92% yield) and 6-fluoro-2-(2-methoxyethoxy)-pyridin-3-ylboronic acid as a semi-crystalline solid. m/z (ESI, +ve ion) 216.1 (M+H)+.

出典