Compounds of the formula ##STR1## wherein R.sub.1 is hydrogen, halogen or alkyl of 1 to 3 carbon atoms; R.sub.2 is hydrogen or alkyl of 1 to 3 carbon atoms; andR.sub.3 is aromatic hydrocarbyl of 6 to 10 carbon atoms or an aromatic heterocycle of 2 to 9 carbon atoms and 1 to 2 nitrogen atoms and/or an oxygen or a sulfur atom, where each of said aromatic substituents may in turn be substituted with one or two alkyls of 1 to 6 carbon atoms, halogen, hydroxyl, trifluoromethyl, halophenyl or alkoxy of 1 to 3 carbon atoms;and non-toxic, pharmacologically acceptable salts thereof formed with inorganic or organic bases; the compounds as well as their salts are useful as analgesics, antipyretics, antithrombotic and antiphlogistics.