Abstract: Oxazole and isoxazole derivatives of the formula ##STR1## wherein A is C.sub.1-6 -alkylene, Het is a 2-R-oxazol-5-yl, 5-R-oxazol-2-yl, 4-R-oxazol-2-yl, 2-R-oxazol-4-yl, 3-R-isoxazol-5-yl or 5-R-isoxazol-3-yl group which is optionally substituted on the heterocyclic ring by a C.sub.1-6 -alkyl group, R is phenyl or thienyl monosubstituted or disubstituted by halogen, trifluoromethyl or C.sub.1-6 -alkylthio, R.sup.1 and R.sup.2 each is a C.sub.1-6 -alkyl group and R.sup.3 is a hydroxy or C.sub.1-6 -alkoxy group or a group of the formula --NR.sup.4 R.sup.5 in which R.sup.4 and R.sup.5 each is a hydrogen atom or a C.sub.1-6 -alkyl group or R.sup.4 and R.sup.5 together with the nitrogen atom to which they are attached is a 5-membered or 6-membered saturated heteromonocyclic ring which may contain an oxygen or sulphur atom or an additional nitrogen atom, and pharmaceutically acceptable salts of the compounds of formula I in which R.sup.3 is a hydroxy group with bases, have anti-arthritic activity.

Abstract: Compounds of the formula ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each individually is hydrogen, or lower alkyl and R.sup.4 is hydroxy, lower alkoxy, aryl-(lower alkoxy), amino, mono(lower alkyl)amino or di(lower alkyl) amino,and pharmaceutically acceptable salts thereof which are useful in the treatment of degenerative joint diseases and of Wilson's disease are described.