Реакция #1994221

Уравнение реакции

2

Ethyl 2,4-Bis(bromomethyl)benzoate

dioxane sulfuric acid

→

3

5-Hydroxymethylphthalide

Растворители

DCM

Условия реакции

Обработка

1. 1
   Температураwas heated
2. 2
   Температураunder reflux for 20 h
3. 3
   ДругоеThe phases were separated
4. 4
   Экстракцияthe aqueous phase was extracted with DCM (5×200 mL)
5. 5
   ПромывкаThe combined organic layers were washed with saturated NaHCO3 (3×200 mL) and brine (1×200 mL)
6. 6
   Сушкаwere dried over MgSO4
7. 7
   ДругоеThe solvent was removed in vacuo

Методика

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).

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