反应 #7105

反应方程式

3-bromo-2-fluorobenzoic acid

trimethylorthoformate

p-toluenesulfonic acid

→

methyl 3-bromo-2-fluorobenzoate

收率 84.0%

溶剂

methanol

反应条件

后处理

1. 1
   温度heated
2. 2
   温度under reflux
3. 3
   其他the mixture was evaporated
4. 4
   其他the residue partitioned between water and Et2O
5. 5
   洗涤The organic layer was washed with sat. sodium hydrogen carbonate solution, water, brine
6. 6
   干燥dried (MgSO4)
7. 7
   其他evaporated

实验过程

A solution of 3-bromo-2-fluorobenzoic acid (0.219 g, 1 mmol) in dry methanol (5 ml) under nitrogen was treated with trimethylorthoformate (0.22 ml, 2 mmol) and p-toluenesulfonic acid (catalytic amount), and then heated under reflux. After 16 h, the mixture was evaporated and the residue partitioned between water and Et2O. The organic layer was washed with sat. sodium hydrogen carbonate solution, water, brine, dried (MgSO4) and evaporated to give methyl 3-bromo-2-fluorobenzoate (0.195 g, 0.84 mmol, 84%): 1H NMR (CDCl3) δ 7.90–7.85 (m, 1H), 7.71–7.65 (m, 1H), 7.10 (dt, 1H, J=8.0, 1.0 Hz) and 3.94 (s, 3H): MS (EI) 232 (M+).

来源