Pyrazolo4,3-d pyrimidine derivative process for its production antihyperlipidemic agent containing it, its intermediate, and process for the production of the intermediate

摘要

A pyrazolo[4,3-d]pyrimidine derivative having the formula:wherein R¹ is lower alkyl, phenyl or substituted phenyl, R² is -A-CO₂R²¹ (wherein A is alkylene having from 1 to 3 carbon atoms which is unsubstituted or substituted by methyl, and R²¹ is lower alkyl having from 1 to 4 carbon atoms), -CH₂CO-phenyl, a saturated or unsaturated, straight chain or branched aliphatic group having from 3 to 16 carbon atoms, phenyl-lower alkyl, -CH₂CN, substituted phenyl-lower alkyl, cyclohexylcyclohexyl, methylcyclohexyl, 4-thia-n-heptyl, 3,6-dioxa-n-octyl, 4-oxo-n-pentyl or(wherein R²² is hydrogen or lower alkyl), and R³ is a saturated or unsaturated, straight chain or branched aliphatic group having from 2 to 22 carbon atoms, phenyl-lower alkyl, substituted phenyl-lower alkyl, substituted or unsubstituted phenyl-methyloxyethyl or 2-hydroxyethyl.