The present invention provides compounds of the general formula I ##STR1## wherein R.sup.1 and R.sup.2, which are the same or different, are unsubstituted or substituted aromatic rings, Alk is a straight-chained or branched lower hydrocarbon chain and Z is a hydrogen atom, with the proviso that when Alk is a straight-chained hydrocarbon chain, Z can also be a lower alkylamino radical of the general formula II ##STR2## in which R.sup.3 and R.sup.4 are the same or different and are hydrogen atoms or straight-chained or branched lower alkyl radicals or R.sup.3 and R.sup.4, together with the nitrogen atom to which they are attached, can also form a ring optionally containing further hetero atoms; and the pharmacologically acceptable salts thereof.The present invention also provides an inventive process for preparing these compounds, as well as pharmaceutical compositions containing them. The compounds I may be used in the therapy of inflammations and they are free of gastrointestinal side effects.