反应详情

Thionyl chloride (42.8 ml, 586 mmol) was added to 5-chloro-2-methylbenzoic acid (25.0 g, 147 mmol). The mixture was stirred under heating to reflux for 1.5 hours. Thereafter, excessive thionyl chloride was distilled away under reduced pressure. The residue was dissolved in methylene chloride (140 ml), and a 40% methylamine aqueous solution (34.2 ml, 440 mmol) was then added dropwise thereto under cooling on ice. Thereafter, the obtained mixture was stirred at 0° C. for 1 day. Thereafter, the reaction solution was extracted with ethyl acetate, and the extract was then washed with a saturated saline solution. The resultant was then dried over anhydrous sodium sulfate, and the solvent was distilled away under reduced pressure. The obtained residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:3 to 3:2), so as to obtain 5-chloro-2,N-dimethylbenzamide (24.2 g; yield: 90%) in the form of a colorless solid.

1. temperatureunder heating
2. temperatureto reflux for 1.5 hours
3. distillationThereafter, excessive thionyl chloride was distilled away under reduced pressure
4. dissolutionThe residue was dissolved in methylene chloride (140 ml)
5. temperatureunder cooling on ice
6. stirringThereafter, the obtained mixture was stirred at 0° C. for 1 day
7. extractionThereafter, the reaction solution was extracted with ethyl acetate
8. washthe extract was then washed with a saturated saline solution
9. dry with materialThe resultant was then dried over anhydrous sodium sulfate
10. distillationthe solvent was distilled away under reduced pressure
11. customThe obtained residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:3 to 3:2)