反应 #1994220

反应方程式

calcium hydroxide

2,4-dimethylbenzoic acid

sulfuric acid

ethanol

→

1

收率 95.0%

Ethyl 2,4-Dimethylbenzoate

收率 95.0%

反应条件

后处理

1. 1
   温度The mixture was refluxed over night
2. 2
   温度cooled down
3. 3
   过滤The suspension was filtered over celite and
4. 4
   浓缩concentrated in vacuo
5. 5
   workup.DISTILLATIONThe crude product was purified by vacuum distillation

实验过程

To a solution of commercially available 2,4-dimethylbenzoic acid (67.8 g, 451 mmol) in 1000 mL of ethanol was added 10 mL of sulfuric acid. The mixture was refluxed over night, cooled down and was neutralized by adding calcium hydroxide in small portions (˜30 g). The suspension was filtered over celite and concentrated in vacuo. The crude product was purified by vacuum distillation yielding 76.4 g (95%) of 1 as a colorless oil: 1H-NMR (400 MHz, CDCl3): δ 1.38 (t, J=7.3 Hz, 3H), 2.34 (s, 3H), 2.57 (s, 3H), 4.33 (q, J=7.2 Hz, 2H), 7.01-7.06 (m, 2H), 7.82 (d, J=8.5 Hz, 1H); 13C-NMR (100 MHz, CDCl3): δ 14.3, 21.3, 21.7, 60.4, 126.3, 126.9, 130.7, 132.4, 140.1, 142.3, 167.6; MS (ESI) m/z=133.0 (100), 132.0 (57), 178.1 (M+, 51).

来源