Compounds of the formula ##STR1## wherein R is hydrogen or methyl; R.sup.1 is hydrogen, C.sub.1 to C.sub.8 linear or branched alkyl or C.sub.1 to C.sub.8 linear or branched alkanoyl; X is oxygen or sulfur; R.sup.2 is selected from the group hydrogen, C.sub.1 to C.sub.18 linear or branched alkyl and the radicals --(CH.sub.2).sub.n --NR.sup.3 R.sup.4, --CH.sub.2 --CH(OH)--CH.sub.2 --OH or a ketal thereof formed from the aldehyde or ketone R.sup.5 R.sup.6 CO, wherein R.sup.3 and R.sup.4 are each independently C.sub.1 to C.sub.6 linear or branched alkyl or R.sup.3 and R.sup.4 taken together with the nitrogen atom of the first radical are attached to form a 5- or 6-membered heterocyclic ring, R.sup.5 and R.sup.6 are each independently hydrogen, C.sub.1 to C.sub.6 linear or branched alkyl, phenyl or benzyl or R.sup.5 and R.sup.6 taken together represent an alkylene bridge of from 4 to 6 carbon atoms; n is an integer of from 2 to 4; and the dotted line represents an optional double bond; and the pharmaceutically acceptable salts thereof. The compounds have anti-inflammatory, analgesic and anti-pyretic activities and, accordingly, are useful in the treatment of inflammation, pain and/or pyrexia.