Novel isoxazole and thiazole compounds and use thereof as drugs

摘要

The present invention relates to novel isoxazole and thiazole compounds having an excellent lysophosphatidic acid (LPA) receptor antagonistic activity represented by general formula Ä1Ü or salts thereof: wherein R1 and R2 represents an optionally substituted alkyl group or the like; R3 represents a hydrogen atom or the like; R4 represent a group selected from the group consisting of (I) optionally substituted phenyl, aryl, or heterocycle, (II) substituted or nonsubstituted alkyl, and (III) substituted or nonsubstituted alkenyl, alternatively, R3 and R4 may form a ring structure together with a carbon atom to which they bind; and X represents an oxygen atom or a sulfur atom, provided that, when R3 is a hydrogen atom, R4 represents a group other than methyl, and the use thereof as a medicine.