Thiazole derivatives for use as anti-inflammatory agents

A 5-membered cyclic compound of the formula: wherein X is oxygen or sulfur, R is hydrogen, substituted or unsubstituted alkyl, etc., R is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, etc., Y is a direct bond, substituted or unsubstituted alkylene, -CO(CH2)n-, etc., the wavy line means (E)-configuration or (Z)-configuration, R is substituted or unsubstituted aryl, etc., Y is substituted or unsubstituted alkylene, etc., R is hydrogen, substituted or unsubstituted alkanoyl, substituted or unsubstituted alkyl, etc., R is hydrogen, etc., or a salt thereof, these compound being able to inhibit infiltration of leukocytes such as eosinophils and lymphocytes, by which being useful for the treatment of various kinds of inflammation.