Synthesis Of The Fasciolicide Nitroxynil

Nitroxynil (4-hydroxy- 3-iodo- 5-nitrobenzonitrile) is a fasciolicide widely used in sheep and cattle. It shows high activity against both mature and immature Fasciola hepatica.Nitroxynil was prepared from p -hydroxybenzaldehyde and p -hydroxybenzoic acid by initial conversion to p -hydroxybenzonitrile in several ways, and the latter was nitrated and then iodinated to give the title compound. Nitroxynil was also prepared from p -hydroxybenzaldehyde by nitration , cyanation and iodination of the product. And the structures of the medium and the title compound have been identified with IR ,MS and element analysis et al.The optimum procedure for the manufacture of nitroxynil was as follows: firstly, p -hydroxyben.zonitrile was obtained by the reaction of p -hydroxybenzaldehyde with hydroxylamine hydrochloride and sodium formate in formic acid; Secondly, p -hydroxybenzoriitrile reacted with nitric acid in glacial acetic acid to give 4-hydroxy- 3-nitrobenzonitrile; And thirdly, 4-hy-droxy- 3-nitrobenzonitrile was iodinated dircetly with iodine in presence of hydrogen peroxide to yield nitroxynil. The results shows that the method has a feature of lower cost and higher yield.