Reacción #1994221

Ecuación de reacción

2

Ethyl 2,4-Bis(bromomethyl)benzoate

dioxane sulfuric acid

→

3

5-Hydroxymethylphthalide

Disolventes

DCM

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawas heated
2. 2
   Temperaturaunder reflux for 20 h
3. 3
   OtroThe phases were separated
4. 4
   Extracciónthe aqueous phase was extracted with DCM (5×200 mL)
5. 5
   LavadoThe combined organic layers were washed with saturated NaHCO3 (3×200 mL) and brine (1×200 mL)
6. 6
   Secadowere dried over MgSO4
7. 7
   OtroThe solvent was removed in vacuo

Procedimiento

A suspension of 2 (22.1 g, 65.7 mmol) in 700 mL of a 1:1 mixture of dioxane/sulfuric acid (1M) was heated under reflux for 20 h. After cooling to room temperature, the mixture was poured into 200 mL of DCM. The phases were separated and the aqueous phase was extracted with DCM (5×200 mL). The combined organic layers were washed with saturated NaHCO3 (3×200 mL) and brine (1×200 mL) and were dried over MgSO4. The solvent was removed in vacuo to yield 8.70 g (83%) of pure 3 as a colorless solid: 1H-NMR (400 MHz, DMSO-d6): δ 4.65 (s, 2H), 5.39 (s, 2H), 5.47 (br s, 1H), 7.51 (d, J=7.8 Hz, 1H), 7.60 (s, 1H), 7.78 (d, J=7.7 Hz, 1H); 13C-NMR (100 MHz, DMSO-d6): δ 62.4, 69.7, 120.0, 123.3, 124.5, 126.9, 147.5, 149.7, 170.5; MS (Cl+ (NH3)) m/z=165.0 (M+H+, 100), 182.0 (M+NH4+, 49).

Fuente