A process for the preparation of a compound of formula I, ##STR00001## wherein R.sub.1 and R.sub.2 are ortho or para substituents, independently selected from the group consisting of hydrogen, hydroxyl, C.sub.1 C.sub.6 alkyl, C.sub.1 C.sub.6 alkoxy, C.sub.7 C.sub.9 aralkoxy, C.sub.2 C.sub.7 alkanoyloxy, C.sub.1 C.sub.6 alkylmercapto, halo and trifuoromethyl; R.sub.3 is hydrogen or C.sub.1 C.sub.6 alkyl 1, 2, 3 or 4; and the dotted line represents optional olefinic unsaturation; comprising hydrogenating a compound of formula III, ##STR00002## in the presence of a nickel or cobalt catalyst at a temperature of about 5.degree. C. to 25.degree. C.