abstract |
Disclosed is a compound of formula (I) and a process for preparing the compound in which Ar represents a 3,4-dichlorophenyl or a 3,4-difluorophenyl and R1 represents a phenyl, a 4-chlorophenyl, a 4-fluorophenyl or a 3,4-difluorophenyl and the other substituents are as defined in the specification. |