NUCLEOPHILIC-SUBSTITUTION REACTIONS OF 5-BROMO-6-METHYLURIDINES

The reactions of the 5-bromo-6-methyl-2',3'-O-isopropylideneuridines 9 and 10 with a number of nucleophiles in hot DMF have been investigate d. With acetate ion as the nucleophile, either the 5-acetoxy-(11,12) o r the 6-acetoxymethyl- (15) products can be obtained in modest yield d epending upon the exact reaction conditions. With nitrogen nucleophile s (aniline or p-methoxylamine) reaction takes place at the 6-methyl ca rbon, whereas with sulfur nucleophiles (thiophenol, thioacetate) only the 5-substituted products are obtained.