反应详情

Under ice-cooling, 0.407 g of 62.4% sodium hydride was added to a mixture of 4.00 g of 2-[3-cycloheptyl-3-(4-dimethylaminophenyl)ureido]-4-methoxy-6-tert-butylphenol, 1.9 ml of chloromethylpivalate and 40 ml of dimethylformamide (DMF), and the temperature of the mixture was gradually raised to room temperature. The mixture was further stirred at room temperature for 2 hours. A saturated saline solution was added to the mixture and the mixture was extracted with ethyl acetate. The extract was washed and dried, and the solvent was removed under reduced pressure. The residue was purified by silica gel column chromatography (solvent; hexane:ethyl acetate=4:1) and precipitated crystals were recrystallized from an isopropyl ether solution. The obtained crystals were dissolved in 10 ml of dichloromethane, and 5 ml of 4N hydrogen chloridedioxane solution was added to the solution. The mixture was evaporated to dryness under reduced pressure. The residue was crystallized from a diethyl ether solution to give 1.65 g of O-pivaloyloxymethyl-2-[3-cycloheptyl-3-(4-dimethylaminophenyl)ureido]-4-methoxy-6-tert-butylphenol hydrochloride (melting point: 114°-118° C. (decomposed)).

1. temperatureUnder ice-cooling
2. additionA saturated saline solution was added to the mixture
3. extractionthe mixture was extracted with ethyl acetate
4. washThe extract was washed
5. customdried
6. customthe solvent was removed under reduced pressure
7. customThe residue was purified by silica gel column chromatography (solvent; hexane:ethyl acetate=4:1)
8. customprecipitated crystals
9. customwere recrystallized from an isopropyl ether solution
10. dissolutionThe obtained crystals were dissolved in 10 ml of dichloromethane
11. addition5 ml of 4N hydrogen chloridedioxane solution was added to the solution
12. customThe mixture was evaporated to dryness under reduced pressure
13. customThe residue was crystallized from a diethyl ether solution