反应详情

3 g of 2-chloro-3-ethylthiomethyl-4-methanesulfonylbenzoic acid, 0.72 g of potassium carbonate, 50 ml of t-amyl alcohol, 1.95 g of N,N'-dicyclohexylcarbodiimide and 4.5 g of a 25% t-amyl alcohol solution of 1-ethyl-5-pyrazolone were mixed and heated under stirring for 4 hours at a temperature of from 70° to 80° C. After cooling, the mixture was distilled under reduced pressure, and 200 ml of water was added to the residue. After filtering off the insolubles, the filtrate was washed with chloroform. Hydrochloric acid was added to the aqueous layer, and the mixture was extracted with chloroform. The extract was dried, and the solvent was distilled off to obtain the desired product as a crude product. The crude product was recrystallized from ethanol to obtain 1.88 g of the purified product. (Melting point: 142°-145° C.)

1. temperatureheated
2. temperatureAfter cooling
3. distillationthe mixture was distilled under reduced pressure, and 200 ml of water
4. additionwas added to the residue
5. filtrationAfter filtering off the insolubles
6. washthe filtrate was washed with chloroform
7. additionHydrochloric acid was added to the aqueous layer
8. extractionthe mixture was extracted with chloroform
9. customThe extract was dried
10. distillationthe solvent was distilled off