Process for the preparation of HBN

Abstract

In a process for the preparation and the isolation of p-hydroxybenzonitrile (HBN), in which a p-halogenated phenol is reacted with cuprous cyanide in a suitable solvent, the reaction mixture obtained after the reaction of the p-halogenated phenol with cuprous cyanide has been substantially completed is contacted with an aqueous solution of a bromide salt and, optionally, an organic diluent, the aqueous and organic phases are separated, HBN is distilled out from the organic phase, an alkali metal cyanide is added to the aqueous phase and CuCN is filtered off from the resulting aqueous phase.

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