反应详情

To a room temperature suspension of 2-chloro-6-ethylbenzaldehyde (13.5 mmol, 2.27 g) in acetonitrile (25 mL) was added a solution of monobasic sodium phosphate (3.4 mmol, 0.465 g) in water (7.5 mL) followed by hydrogen peroxide (1.8 mL, 30%). Then, a solution of sodium chlorite (23.7 mmol, 2.15 g) in water (20 mL) was added dropwise at 0° C. while maintaining the temperature below 3° C. After addition, the yellow suspension was stirred for 15 h at 0° C. to room temperature. At this time TLC analysis of the mixture indicated the absence of starting material. Then, a solution of sodium bisulfite (20.5 mmol, 2.8 g) in water (10 mL) was added dropwise at 0° C. until the yellow color disappeared (KI-paper positive). Cooling is essential to control the exothermic reaction. After 1 h, the solvent was removed under vacuum. The neutral impurities were extracted with diethyl ether (200 mL). Then, the basic aqueous solution was neutralized with 10% HCl to pH ˜1. The precipitated white solid was collected by filtration and dried at in air to afford 2.415 g (97% yield) of 2-chloro-6-ethylbenzoic acid as an amorphous white solid. EI-HRMS m/e calcd for C9H9ClO2 (M+) 184.0291, found 184.0295.

1. temperaturewhile maintaining the temperature below 3° C
2. additionAfter addition
3. temperatureCooling
4. customthe exothermic reaction
5. waitAfter 1 h
6. customthe solvent was removed under vacuum
7. extractionThe neutral impurities were extracted with diethyl ether (200 mL)
8. filtrationThe precipitated white solid was collected by filtration
9. customdried at in air