NOVEL PYRIMIDINE NUCLEOSIDE COMPOUND OR ITS SALT.

摘要

A novel pyrimidine nucleoside compound, or its salt, of the general formula: (1) wherein one of X and Y is a cyano while the other is a hydrogen atom; and one of R¹ and R² is a hydrogen atom, a carbonyl having an alkyl monosubstituted with amino, or a group of the formula (R³)(R⁴)(R⁵)Si- while the other is a silyl of the formula (R⁶)(R⁷)(R⁸)Si-, or alternatively R¹ and R² together represent a group of the formula -Si(R⁹)(R¹⁰)- and may form a six-membered cyclic group, provided that each of R³, R⁴, R⁵, R⁶, R⁷ and R⁸ is an alkyl, a cycloalkyl, an aryl or an alkyl substituted with one or two aryls, and that R⁹ and R¹⁰ are alkyls. The provided novel pyrimidine nucleoside compounds exhibit antitumor efficacy higher than those of conventional pyrimidine nucleoside compounds.