反応 #1994221

反応方程式

2

Ethyl 2,4-Bis(bromomethyl)benzoate

dioxane sulfuric acid

→

3

5-Hydroxymethylphthalide

溶媒

DCM

反応条件

後処理

1. 1
   温度was heated
2. 2
   温度under reflux for 20 h
3. 3
   その他The phases were separated
4. 4
   抽出the aqueous phase was extracted with DCM (5×200 mL)
5. 5
   洗浄The combined organic layers were washed with saturated NaHCO3 (3×200 mL) and brine (1×200 mL)
6. 6
   乾燥were dried over MgSO4
7. 7
   その他The solvent was removed in vacuo

実験手順

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).

出典