The pharmaceutical composition according to claim 8, wherein R1 is a monosubstituted phenyl selected from the group consisting of 4-azidophenyl, 4-bromophenyl, 4-chlorophenyl, 4-cyanophenyl, 4-ethylphenyl, 4-fluorophenyl, 4-iodophenyl, 4-(phenycarbonyl)-phenyl, and 4-(1-ethoxy)ethylphenyl.