| abstract |
The present invention relates to a compound represented by the formula (I):n nor a pharmacologically acceptable salt thereof, wherein R 1 , R 2 , R 3 , and R 4 are the same or different and each represent a hydrogen atom or a C1-6 alkyl group; X 1 represents a C1-6 alkylene group that may be substituted; X a represents a methoxy group or a fluorine atom; X b represents an oxygen atom or a methylene group, provided that X b is only an oxygen atom when X a is a methoxy group; and Ar 1 represents an aryl group, pyridinyl group, aryloxy group, or pyridinyloxy group that may have a substituent such as a halogen atom; and to use of the compound or salt as a pharmaceutical agent. |