The present invention relates to compounds of formula (I): wherein R.sub.1 is hydroxy, C.sub.1-4 alkoxy, amino, C.sub.1-4 alkyl-amino, di C.sub.1-4alkylamino, benzyloxy or C.sub.2-C.sub.7 alkanoyl, R.sub.2 is C.sub.1-4 alkyl, C.sub.1-4 alkoxy, C.sub.1-4 alkoxy C.sub.1-4alkoxy, CF.sub.3, halogen, C.sub.1-4alkylamino, di C.sub.1-4alkylamino, di C.sub.1-4 alkylamino C.sub.1-4 alkoxy or N--C.sub.1-4 alkoxy C.sub.1-4 alkyl-N--C.sub.1-4 alkylamino, N--C.sub.1-4 alkyl-piperazinyl, morpholinyl or pyrrolidinyl-C.sub.1-4 alkoxy, wherein the C.sub.1-4 alkyl radicals in R.sub.2 are optionally further substituted by C.sub.1-4 alkyl, halogen, cyano, amino, alkoxy or alkylthio, X is N or O, Y is N, O or CH, Z is N or CH, and W is N or CH, provided that (a) R.sub.1 is not hydroxy or C.sub.1-4 alkoxy when R.sub.2 is CF.sub.3, X is O, Y is CH, Z is N and W is CH, (b) R.sub.1 is not hydroxy or C.sub.1-4 alkoxy when R.sub.2 is CF.sub.3 or chloro, X is N, Y is O, Z is CH and W is CH, (c) R.sub.1 is not hydroxy when R.sub.2 is CF.sub.3, X is O, Y is N, Z is CH and W is CH and (d) X and Y are not simultaneously O, the salts thereof; their preparation, their use and pharmaceutical compositions containing them. ##STR00001##