| abstract |
Provided is a compound for preventing or treating flaviviridae virus infection. A modified nucleoside represented by the following formula and / or a prodrug thereof: [R 1 to R 3 are each independently H, phosphate, linear / branched / cyclic alkyl, acyl, CO-alkyl, etc., and at least one of R 2 and R 3 is not H; Y 1 is H, Br, OH, NH2 and the like; Y 3 are each independently H, F, Cl, Br, etc.; X 1 is an alkyl, CN, OH, NH2 and the like; X 2 is H, alkyl, CH2F, CH2Cl, OH, NH2, etc.] [Selection figure] None |