Patent ID: 8039614

Claim:
A method for producing a 4′-C-substituted-2-haloadenosine compound represented by formula [I]: wherein X represents a fluorine or chlorine atom, R 1 represents an ethynyl group or a cyano group, and R 2 represents hydrogen, the method comprising: a first step of protecting hydroxyl groups at the 3′- and 5′-positions of a compound represented by formula [IV]: wherein R 1 represents an ethynyl group or a cyano group, to provide a compound represented by formula [V]: wherein P represents a protective group, and R 1 represents an ethynyl group or a cyano group; a second step of treating the amino group at the 2-position of the compound represented by formula [V] with a nitrite derivative and a halogen reagent to introduce a halogen atom at the 2-position thereof, to provide a compound represented by formula [VI]: wherein P represents a protective group, X represents a fluorine or chlorine atom, and R 1 represents an ethynyl group or a cyano group; and a third step of removing the protective groups of the resultant compound to provide a compound represented by formula [I], wherein the nitrite derivative and the halogen reagent in the second step are selected from the group consisting of sodium nitrite and tetrafluoroboric acid, a nitrous acid ester and hydrogen fluoride-pyridine, a combination of antimony trichloride and t-butyl nitrite in an organic solvent and a combination of acetyl chloride and benzyltriethylammonium nitrite in an organic solvent.