Reaction #1994220

Reaction equation

calcium hydroxide

2,4-dimethylbenzoic acid

sulfuric acid

ethanol

→

1

Yield 95.0%

Ethyl 2,4-Dimethylbenzoate

Yield 95.0%

Conditions

Workup

1. 1
   TemperatureThe mixture was refluxed over night
2. 2
   Temperaturecooled down
3. 3
   FiltrationThe suspension was filtered over celite and
4. 4
   Concentrationconcentrated in vacuo
5. 5
   workup.DISTILLATIONThe crude product was purified by vacuum distillation

Procedure

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).

Source