5-Fluorouracil → 1-(p-Toluenesulfonyl)-5-fluorouracil

Reaction equation

[F:1][C:2]1[C:3](=[O:9])[NH:4][C:5](=[O:8])[NH:6][CH:7]=1.C(=O)([O-])[O-].[K+].[K+].[C:16]1([CH3:26])[CH:21]=[CH:20][C:19]([S:22](Cl)(=[O:24])=[O:23])=[CH:18][CH:17]=1>O1CCOCC1>[F:1][C:2]1[C:3](=[O:9])[NH:4][C:5](=[O:8])[N:6]([S:22]([C:19]2[CH:20]=[CH:21][C:16]([CH3:26])=[CH:17][CH:18]=2)(=[O:24])=[O:23])[CH:7]=1

Participants

Procedure

2.6 g (0.02 mole) of 5-fluorouracil and 1.28 g (0.01 mole) of anhydrous potassium carbonate were suspended in 50 ml. of dioxane and reacted with 3.82 g (0.02 mole) of p-toluenesulfonyl chloride in the same manner as in Example 10. There was obtained 3.54 g (62.3% yield) of 5-fluoro-1-(p-toluenesulfonyl)uracil. Recrystallization of the product from methanol-chloroform gave leaflets melting at 241°-242°C. The results of an elementary analysis thereof were well in agreement with the calculated value as follows: