Реакция #7105

Уравнение реакции

3-bromo-2-fluorobenzoic acid

trimethylorthoformate

p-toluenesulfonic acid

→

methyl 3-bromo-2-fluorobenzoate

Выход 84.0%

Растворители

methanol

Условия реакции

Обработка

1. 1
   Температураheated
2. 2
   Температураunder reflux
3. 3
   Другоеthe mixture was evaporated
4. 4
   Другоеthe residue partitioned between water and Et2O
5. 5
   ПромывкаThe organic layer was washed with sat. sodium hydrogen carbonate solution, water, brine
6. 6
   Сушкаdried (MgSO4)
7. 7
   Другоеevaporated

Методика

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+).

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