反应 #1704500

反应方程式

5-bromo-2-ethoxy-pyridine

4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester

Cs2CO3

→

desired product

6-Ethoxy-3′,6′-dihydro-2′H-[3,4′]bipyridinyl-1′-carboxylic acid tert-butyl ester

溶剂

DMF

H2O

反应条件

后处理

1. 1
   其他After that time, the solvent is evaporated
2. 2
   洗涤washed with brine
3. 3
   干燥After drying over sodium sulphate
4. 4
   其他the solvent is removed in vacuo
5. 5
   其他the residue is purified by column chromatography (silica gel; gradient PE/EtOAc 20:1→10:1)

实验过程

Under inert gas atmosphere 5.00 g (23.3 mmol) 5-bromo-2-ethoxy-pyridine are added to a mixture of 7.19 g (23.3 mmol) 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester, 95 mg (1.2 mmol) PdCl2(dppf)xCH2Cl2 and 15.2 g (46.5 mol) Cs2CO3 in 50 mL DMF and 10 mL H2O. The mixture is stirred for 12 h at 80° C. After that time, the solvent is evaporated, the residue taken up in DCM and washed with brine. After drying over sodium sulphate, the solvent is removed in vacuo and the residue is purified by column chromatography (silica gel; gradient PE/EtOAc 20:1→10:1) to yield the desired product which was directly used in the next step.

来源