| 摘要 |
<p>Compounds of the formula (1) : <CHEM> and pharmaceutically acceptable salts thereof are described wherein R<1> is C1-6alkyl, C2-6alkenyl, C3-5cycloalkylC1-4alkyl, phenylC1-4alkyl or C1-4alkyl substituted by 1 to 6 fluoro groups; R<2> is hydrogen, C1-6alkyl, C1-6alkylthio, C1-6alkoxy, nitro or -NR<3>R<4>; and R<3> and R<4> are independently hydrogen or C1-4alkyl optionally substituted by hydroxy provided that the carbon atom adjacent to the nitrogen atom is not substituted by hydroxy; with the proviso that R<1> is not methyl or ethyl when R<2> is hydrogen. Processes for their preparation, pharmaceutical compositions containing them and their use as medicaments are described.</p> |
