HETEROCYCLIC COMPOUNDS AND CEREBRAL FUNCTION IMPROVERS CONTAINING THE SAME AS THE ACTIVE INGREDIENT

摘要

Heterocyclic compound represented by the formula I <CHEM> wherein <CHEM> represents <CHEM> <CHEM> or the like; R1 represents hydrogen atom, C1-C6 alkyl or benzyloxy; R2 represents methyl or nil; R3 represents hydrogen atom, C1-C6 alkyl, C2-C6 alkenyl, C3-C8 cycloalkyl or -CH2R5 Äwherein R5 represents phenyl (which may be substituted with C1-C6 alkyl, halogen atom or cyano)Ü or thienyl; R4 represents C1-C6 alkyl, C2-C6 alkenyl, C3-C8 cycloalkyl or -CH2R6 Äwherein R6 represents phenyl (which may be substituted with C1-C6 alkyl, halogen atom or cyano) , naphtyl or thienylÜ; or R3 is coupled with R4.