反应详情

In 75 ml of pyridine-acetone (pyridine:acetone=2:1) were dissolved 20 g (76 mmol) of ethyl 5-fluoro-6-acetoxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate and 11.4 g (91 mol) of (Z)-5-methylfurfuraldoxime, and the solution was stirred at room temperature for 4 days. The reaction solution was concentrated under reduced pressure, and the residue was treated with water. Crystals precipitated were collected by filtration and washed with water. The crystals were dried under reduced pressure and dissolved in acetone, and insoluble matters were filtered off. The filtrate was concentrated, and the residue was chromatographed on silica gel with chloroform-acetone (7:1), followed by recrystallization from ethyl acetate-hexane to yield 4.6 g of ethyl 5-fluoro-6-[(Z)5-methylfurfurylideneaminooxy]-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate. m.p. 163°-164° C.

1. concentrationThe reaction solution was concentrated under reduced pressure
2. additionthe residue was treated with water
3. customCrystals precipitated
4. filtrationwere collected by filtration
5. washwashed with water
6. customThe crystals were dried under reduced pressure
7. dissolutiondissolved in acetone
8. filtrationinsoluble matters were filtered off
9. concentrationThe filtrate was concentrated
10. customthe residue was chromatographed on silica gel with chloroform-acetone (7:1)
11. customfollowed by recrystallization from ethyl acetate-hexane