Reaktion #1994220

Reaktionsgleichung

calcium hydroxide

2,4-dimethylbenzoic acid

sulfuric acid

ethanol

→

1

Ausbeute 95.0%

Ethyl 2,4-Dimethylbenzoate

Ausbeute 95.0%

Reaktionsbedingungen

Aufarbeitung

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

Vorschrift

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).

Quelle