反応 #2501402

反応方程式

hexane

methanol

4-bromoisophthalic acid

sulfuric acid

methanol

→

4-bromoisophthalic acid dimethyl ester

収率 90.0%

反応条件

後処理

1. 1
   温度The solution mixture was heated
2. 2
   温度at reflux temperature for 24 hours
3. 3
   その他the methanol solvent was removed under reduced pressure
4. 4
   抽出The solution was extracted with ethyl acetate
5. 5
   洗浄The extract was washed with water
6. 6
   乾燥dried over sodium sulfate (Na2SO4)
7. 7
   その他Removal of solvent
8. 8
   その他gave oil, which
9. 9
   その他solidified at ambient temperature

実験手順

To a solution of 4-bromoisophthalic acid 201 (10 g, 40.8 mmol) in methanol (150 mL) was added concentrated sulfuric acid (3.5 mL). The solution mixture was heated at reflux temperature for 24 hours. After the reaction was complete, the methanol solvent was removed under reduced pressure. The residue was made basic with saturated sodium bicarbonate (NaHCO3). The solution was extracted with ethyl acetate. The extract was washed with water and dried over sodium sulfate (Na2SO4). Removal of solvent gave oil, which solidified at ambient temperature. The solid was titurated twice with 20 mL of methanol and hexane (1:3) to give 8 g (90%) of 4-bromoisophthalic acid dimethyl ester 202: 1H NMR (400 MHz, CDCl3) δ 3.93 (s, 3H), 3.93 (s, 3H), 7.74 (d, J=8 Hz, 1H), 7.95 (dd, J=2 Hz, J=8 Hz, 1H), 8.43 (d, J=2 Hz, 1H).

出典