5-SUBSTITUTED URIDINE DERIVATIVES AND INTERMEDIATES FOR THEIR PREPARATION

摘要

5-Substituted uridine derivative represented by general formula (I) [wherein X represents F or CF3, R1 and R2 each represents -OSi-(R4)(R5)(R6) (wherein R4, R5 and R6 each represents a C1 to C10 alkyl group or the like), OH, an aminoacyloxy group amino group of which may be replaced by a lower alkyl group, or a carboxylalkylcarbonyloxy group, R3 represents -OSi-(R4)(R5)(R6), H, OH, an aminoacyloxy group amino group of which may be replaced by a lower alkyl group, or a carboxylalkylcarbonyloxy group, with at least one of R1, R2 and R3 being -OSi-(R4)(R5)(R6), provided that, when X is F, R3 is not H], intermediates for their preparation, processes for preparing them, and antitumor agents containing them as effective ingredients are disclosed.