Reacción #7105

Ecuación de reacción

3-bromo-2-fluorobenzoic acid

trimethylorthoformate

p-toluenesulfonic acid

→

methyl 3-bromo-2-fluorobenzoate

Rendimiento 84.0%

Disolventes

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturaheated
2. 2
   Temperaturaunder reflux
3. 3
   Otrothe mixture was evaporated
4. 4
   Otrothe residue partitioned between water and Et2O
5. 5
   LavadoThe organic layer was washed with sat. sodium hydrogen carbonate solution, water, brine
6. 6
   Secadodried (MgSO4)
7. 7
   Otroevaporated

Procedimiento

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+).

Fuente