PRODUCTION OF CYTOSINE NUCLEOSIDE

摘要

PURPOSE:To obtain the titled compound useful as a medicine or its synthetic intermediate, in high yield, by reacting uridine with a hexaalkyldisilazane and an acid amide in a closed vessel, thereby carrying out the amination of the 4-site of uridine under low pressure at a stroke. CONSTITUTION:The objective compound can be produced by reacting (A) uridine which may be protected at the OH group with (B) a hexaalkyldisilazane [preferably the compound of formula (R<1> is alkyl), especially hexamethyldisilazane and (C) an acid amide {e.g. the compound of formula R<2>CONHR<3> [R<2> and R<3> are H, (substituted) alkyl, aralkyl, aryl or alkenyl], e.g. acetamide, etc.} in a closed vessel preferably at 90-170 deg.C and 1-25kg/cm<2> pressure, and if necessary, removing the protecting group. The amounts of the components B and C are 2-10mol and 0.1-3mol per 1mol of the component A, respectively.