A compound of the general formula I wherein R1 represents a substituent selected from the group consisting of halogen, hydroxy, mercapto, trifluoromethyl, amino, (C1-C3)alkyl, (C2-C3)olefinic group, (C1-C3)alkoxy, (C1-C3)alkylthio, (C1-C6)alkylamino, (C1-C3)alkoxycarbonyl, cyano, —CONH2, phenyl, and nitro; R2 represents one or more, same or different substituents selected from the group consisting of hydrogen, halogen, hydroxy, mercapto, trifluoromethyl, amino, (C1-C3)alkyl, (C2-C3)olefinic group, (C1-C3)alkoxy, (C1-C3)alkylthio, (C1-C6)alkylamino, (C1-C3)alkoxycarbonyl, cyano, —CONH2, phenyl, and nitro; R3 represents one or more, same or different substituents selected from the group consisting of hydrogen, halogen, hydroxy, mercapto, trifluoromethyl, cyano, carboxy, carbamoyl, (C1-C10)alkyl, (C2-C10)olefinic group, (C3-C8)monocyclic hydrocarbon group, (C1-C10)alkoxy, (C1-C10)alkylthio, (C1-C10)alkoxycarbonyl, and phenyl; R4 represents hydrogen, (C1-C6)alkyl, (C2-C6)olefinic group, or (C3-C6)monocyclic hydrocarbon group; R5 represents one or more, same or different substituents selected from the group consisting of hydrogen and R1; X represents oxygen, sulphur, or N—OH; and salts thereof with pharmaceutically acceptable acids, hydrates and solvates, may be used in the prophylaxis or treatment of inflammatory diseases.