反应详情

A mixture of 2.0 g of 1-amidino-4-piperidinepropionic acid hydrochloride and 1.29 g of p-acetaminophenol was dissolved in 20 ml of dry pyridine. To the solution was added with stirring and ice-cooling 1.75 g of dicyclohexylcarbodiimide, and the resulting mixture was stirred overnight at room temperature. The reaction mixture was filtered to give crystals which were then washed with ethyl acetate and further with ether and dried. The crystals were refluxed with 600 ml of dichloromethane, and the resulting mixture was filtered to give an insoluble substance. The substance was washed with dichloromethane and recrystallized from methanol-ethyl acetate to obtain 1.5 g (yield: 48.4%) of p-acetaminophenyl 1-amidino-4-piperidinepropionate hydrochloride as colorless crystals having a melting point of 258° to 261° C.

1. additionTo the solution was added
2. stirringthe resulting mixture was stirred overnight at room temperature
3. filtrationThe reaction mixture was filtered
4. customto give crystals which
5. washwere then washed with ethyl acetate and further with ether
6. customdried
7. temperatureThe crystals were refluxed with 600 ml of dichloromethane
8. filtrationthe resulting mixture was filtered
9. customto give an insoluble substance
10. washThe substance was washed with dichloromethane
11. customrecrystallized from methanol-ethyl acetate