Compounds of the formula ##STR1## wherein Ar is pyridyl or phenyl substituted by halogen, halo-C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, or carboxy-C.sub.1 -C.sub.4 -alkyl, n is zero, one or two, R.sub.1 is hydrogen, C.sub.1 -C.sub.4 -alkyl, heterocyclyl-C.sub.2 -C.sub.4 -alkyl, amino-C.sub.2 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkylamino-C.sub.2 -C.sub.4 -alkyl, di-C.sub.1 -C.sub.4 -alkylamino-C.sub.2 -C.sub.4 -alkylor C.sub.1 -C.sub.4 -alkanoyl, and R.sub.2 is hydrogen, carboxy-C.sub.1 -C.sub.4 -alkyl, or C.sub.1 -C.sub.4 -alkoxy-carbonyl-C.sub.1 -C.sub.4 -alkyl are disclosed as well as their preparation, pharmaceutical compositions containing the same and the use thereof as antirheumatic agents.