反応 #10758

反応方程式

5-Bromo-2,4-dimethoxybenzaldehyde

Ethylene glycol

→

2-(5-bromo-2,4-dimethoxy-phenyl)-[1,3]dioxolane

収率 92.0%

溶媒

benzene

反応条件

後処理

1. 1
   温度the solution was refluxed with a Dean-Stark trap
2. 2
   温度the reaction was cooled
3. 3
   洗浄washed with water (1×20 mL)
4. 4
   乾燥The organic phase was dried over sodium sulfate
5. 5
   ろ過filtered
6. 6
   濃縮concentrated
7. 7
   その他dried

実験手順

Ex-46A: 5-Bromo-2,4-dimethoxybenzaldehyde (4.92 g, 20.1 mmol) was dissolved in benzene (41 mL). Ethylene glycol (3 mL, 54 mmol) and p-toluenesulfonic acid (25 mg, 0.13 mmol) were added and the solution was refluxed with a Dean-Stark trap attached. After 6 h, the reaction was cooled and washed with water (1×20 mL), saturated, aqueous NaHCO3 (1×20 mL), and water (1×20 mL). The organic phase was dried over sodium sulfate, filtered, concentrated, and dried to provide 5.32 g of 2-(5-bromo-2,4-dimethoxy-phenyl)-[1,3]dioxolane as a faint yellow oil which solidified upon standing (92% yield). 1H-NMR (CDCl3) δ 7.67 (s, 1H), 6.47 (s, 1H), 6.06 (s, 1H), 4.11–4.13 (m, 2H), 3.98–4.03 (m, 2H), 3.91 (s, 3H), 3.87 (s, 3H). HRMS (ES+) Calcd. for C11H13BrO4: 289.0075. Found: 289.0077.

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