反应详情

2N Aqueous sodium hydroxide solution (2.28 ml, 0.0046 mol) was added to a solution of (E)-3-(1-methyl-7-oxo-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-n-propoxycinnamic acid t-butyl ester (0.40 g, 0.00088 mol) in methanol (2.3 ml) and the mixture was heated under reflux for 18 hours. The methanol was removed by evaporation under vacuum, the residue dissolved in water (25 ml), and the solution extracted with ethyl acetate (4×15 ml). The aqueous layer was separated, acidified to pH 1 with hydrochloric acid, and then extracted with a mixture of methanol and ethyl acetate (3:97, 4×20 ml). The organic extracts were combined, dried (Na2SO4) and evaporated under vacuum, then the residue crystallised from ethyl acetate to give the title compound as a white solid (0.27 g, 77%), m.p. 229°-230° C. Found: C,63.64; H,5.98; N,14.14. C21H25N4O4 requires C,63.46; H,6.34; N,14.10%.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 18 hours
3. customThe methanol was removed by evaporation under vacuum
4. dissolutionthe residue dissolved in water (25 ml)
5. extractionthe solution extracted with ethyl acetate (4×15 ml)
6. customThe aqueous layer was separated
7. extractionextracted with a mixture of methanol and ethyl acetate (3:97, 4×20 ml)
8. dry with materialdried (Na2SO4)
9. customevaporated under vacuum
10. customthe residue crystallised from ethyl acetate