abstract |
A compound of the formula (I): in which X represents O or S; R 1 represents C 1-6 alkyl, C 3-8 cycloalkyl, C 3-8 cycloalkylmethyl or C 3-8 cycloalkenyl, any of which may be optionally substituted by one or more methyl groups or halogen atoms or R 1 represents aryl, 4- (diethylamino) sulfonylphenyl , 2,6-Difluorophenyl, 4-methoxyphenyl, 3-difluoromethylthiophenyl, 4-cyanophenyl, heteroaryl, 5-chloro-4-methoxy-thiophene-3-yl, 2-isopropyl-1,3-thiazol-4-yl, 5 -trifluoromethylfuran-2-yl, 5-methylsulfonyl-thiophene-2-yl, 5-methylthio-thiophene-2-yl or 5-ethyl-isoxazol-3-yl; R2 represents hydrogen, methyl, which can be in both α and β configuration, or methylene; R3 and R4 are the same or different and each independently represents hydrogen, halogen or a methyl group, and represents a single or double bond; or a physiologically acceptable salt or solvate thereof. |