Compounds of formula (I), wherein A represents N or CH; R.sup.1 and R.sup.2 independently represent C.sup.1-4 alkyl, halo or CF.sub.3 ; R.sup.3 represents C.sub.1-4 alkyl (optionally substituted), C.sub.3-7 cycloalkyl, CF.sub.3 or aryl; R.sup.4 represents H, C.sub.3-7 cycloalkyl or C.sub.1-6 alkyl (optionally substituted); and their pharmaceutically acceptable derivatives; are useful in the treatment of, inter alia, neurodogenerative disorders. ##STR1##
式(I)的化合物,其中A代表N或CH;R.sup.1和R.sup.2分别代表C.sup.1-4烷基,卤素或CF.sub.3;R.sup.3代表C.sub.1-4烷基(可选取代),C.sub.3-7环烷基,CF.sub.3或芳基;R.sup.4代表H,C.sub.3-7环烷基或C.sub.1-6烷基(可选取代);以及它们的药学上可接受的衍
生物;在治疗神经退行性疾病等方面是有用的。