A process for preparation of a compound of formula (I), both as the isomeric mixture and individual isomers, ##STR00001## wherein Q is .dbd.CR.sub.8-- or .dbd.N--; each R.sub.1, R.sub.2, R.sub.3, R.sub.4 is independently selected from hydrogen, halogen, hydroxy; nitro; C.sub.1-C.sub.6 alkyl optionally substituted with hydroxy; alkylthio C.sub.1-C.sub.6; C.sub.1-C.sub.6 alkoxy optionally substituted with halogen or C.sub.1-C.sub.6 alkoxy; phenyl-C.sub.1-C.sub.6 alkyl; phenyl-C.sub.1-C.sub.6 alkoxy; and --N(RaRb) wherein each Ra and Rb is independently hydrogen or C.sub.1-C.sub.6 alkyl or Ra and Rb, taken together with the nitrogen atom they are linked to, form a saturated heterocyclic ring; and each R.sub.5, R.sub.6, R.sub.7, R.sub.8 is independently selected from hydrogen, halogen, hydroxy; C1-C6 alkyl optionally substituted with hydroxy; alkylthio C.sub.1-C.sub.6; C.sub.1-C.sub.6 alkoxy optionally substituted with halogen; C.sub.1-C.sub.6 alkyl-carbonyl, C.sub.1-C.sub.6 alkoxy-carbonyl, and oxazol-2-yl; comprising converting a compound of formula (IV), ##STR00002## to said compound of formula (I), in the presence of a catalyst, if necessary in an organic solvent.