Collect. Czech. Chem. Commun. 1989, 54, 1358-1362

Reaction of 6-azauridine with thionyl chloride in hexamethylphosphoramide

Pavel Drašar and Jiří Beránek

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


Reaction of 6-azauridine (I) with a mixture of thionyl chloride and hexamethylphosphoramide afforded 5'-chloro-5'-deoxy-6-azauridine (II) and a mixture of SR- and SS-isomers of 5'-chloro-5'-deoxy-2',3'-O-sulfinyl-6-azauridine (IIIa and IIIb) which were separated by column chromatography on silica gel; compounds IIIa and IIIb also arose in the reaction of compound II with diphenyl sulfite. Removal of the cyclic sulfinyl group from the isomeric sulfites IIIa and IIIb gave compound II; reaction of IIIa and IIIb with imidazole in dimethylformamide afforded the 5'-chloro-5'-deoxy-2,2'-anhydro derivative IV.