Synthesis of 6-alkyluridines from 6-cyanouridine via zinc(II) chloride-catalyzed nucleophilic substitution with alkyl grignard reagents

6-Cyanouracil derivatives underwent a direct nucleophilic substitution reaction with alkyl Grignard reagents in the presence of zinc(II) chloride as a catalyst to form the corresponding 6-alkyluracils. This methodology is applicable to sugar-protected 6-cyanouridine and 6-cyano-2′-deoxyuridine without the protection at the N³-imide and provides a facile and general access to versatile 6-alkyluracil and 6-alkyluridine derivatives.