NEW PYRIMIDINE-NUCLEOSID DERIVATIVES

摘要

A novel pyrimidine nucleoside derivative of formula (1) or (2) and a salt thereof, wherein R<1> represents amino which may be substituted with hydroxy or acyl; R<2> represents hydrogen or C<5> to C<8> alkyl; R<3> represents hydrogen or hydroxy; and R4 and R5 represent each hydrogen or they may be combined together to represent -R6R<6'>Si-O-SiR7R<7'>-, wherein R6, R<6'>, R7 and R<7'> each represents lower alkyl. This compound has an excellent antitumor effect or serves as a useful intermediate for the synthesis of antitumor drugs.