反応 #1994220

反応方程式

calcium hydroxide

2,4-dimethylbenzoic acid

sulfuric acid

ethanol

→

1

収率 95.0%

Ethyl 2,4-Dimethylbenzoate

収率 95.0%

反応条件

後処理

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

実験手順

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).

出典