To provide an efficient method for producing a protected 2'- deoxycytidine derivative by which disadvantages in practical use as an industrial method for production such as purification by column chromatography using a halogen solvent in a conventional technique are eliminated without limitation in feed rate.
This simple method for producing the protected 2'-deoxycytidine derivative comprises regulating the equivalent of a reactional reagent to be used, carrying out a reaction, adding a specific mixed solvent of a solvent dissolving the reactional mixture with a solvent without dissolving the protected 2'-deoxycytidine derivative which is the objective substance to the resultant reactional mixture, crystallizing and isolating only the objective substance.
TANIGAWA HIROHARU
KONO TOSHIYUKI
