Cyanodibenzo[1,4]dioxines: A New Family of Synthons for Substituted Dibenzo[1,4]dioxines

Cyanodibenzo[l,4]dioxines, previously unreported, are prepared quantitatively from catechols by nucleophilic fluorodisplacement from 2,3- and 3,4-difluorobenzonitriles, involving meta-fluorodisplacement, in DMF at 130 °C in the presence of potassium carbonate; the cyano-substituted dioxines can be transformed to other substituted dibenzo[l,4]dioxines.