反应详情

3.3 Grams of 3,4-dimethoxybenzoic acid was dissolved in 30 ml of dimethylformamide, then 2.4 g of triethylamine was added to this solution. Under ice-cooled condition, to this solution was added dropwise 2.75 g of isobutyl chloroformate with stirring, and further stirred for 30 minutes. Then to this reaction mixture was added dropwise a DMF solution containing 5.8 g of o-methoxycarbonyl-α-(1-piperazinyl)acetanilide and stirred for 5 hours. The reaction mixture was concentrated to dryness and subjected to extraction by adding chloroform and 1 N-sodium hydroxide. The chloroform layer was washed with water, dried and removed by distillation, the residue obtained was crystallized by adding ethyl acetate and the crystals formed were collected by filtration. Recrystallized from ethanol to obtain 2.3 g of o-methoxycarbonyl-α-[4-(3,4-dimethoxybenzoyl)-1-piperazinyl]acetanilide in the form of colorless needle-like crystals. Melting point: 167.5°-169.0° C.

1. temperatureUnder ice-cooled condition
2. stirringfurther stirred for 30 minutes
3. stirringstirred for 5 hours
4. concentrationThe reaction mixture was concentrated to dryness
5. extractionsubjected to extraction
6. additionby adding chloroform and 1 N-sodium hydroxide
7. washThe chloroform layer was washed with water
8. customdried
9. customremoved by distillation
10. customthe residue obtained
11. customwas crystallized
12. additionby adding ethyl acetate
13. customthe crystals formed
14. filtrationwere collected by filtration
15. customRecrystallized from ethanol