反应详情

3.3 Grams of 3,4-dimethoxybenzoic acid was dissolved in 30 ml of dimethylformamide, and to this solution was added 2.4 g of triethylamine. Under ice-cooled condition with stirring, 2.75 g of isobutyl chloroformate was added dropwise and the mixture obtained was stirred for 30 minutes. To this reaction mixture was added dropwise a dimethylformamide solution of 5.5 g of o-carbamoyl-α-(1-piperazinyl)acetanilide and was stirred for 5 hours. The reaction mixture was concentrated to dryness and extracted with chloroform-1N sodium hydroxide aqueous solution. The chloroform layer was washed with water, dried and chloroform was removed by distillation, the residue thus obtained was purified by a silica gel column chromatography and the product obtained was converted into a hydrochloride by adding hydrochloric acid-ethanol, recrystallized from water-acetone to obtain 1.5 g of o-carbamoyl-α-[4-(3,4-dimethoxybenzoyl)-1-piperazinyl]acetanilide monohydrochloride monohydrate in the form of colorless needle-like crystals. Melting point: 122.0°-125.0° C. (decomposed).

1. temperatureUnder ice-cooled condition
2. customthe mixture obtained
3. stirringwas stirred for 30 minutes
4. stirringwas stirred for 5 hours
5. concentrationThe reaction mixture was concentrated to dryness
6. extractionextracted with chloroform-1N sodium hydroxide aqueous solution
7. washThe chloroform layer was washed with water
8. customdried
9. customchloroform was removed by distillation
10. customthe residue thus obtained
11. customwas purified by a silica gel column chromatography
12. customthe product obtained
13. customrecrystallized from water-acetone