Research in the isoxazole series

3,5-Diarylisoxazoles in acetic acid are smoothly converted to 4-chloro derivatives by the action of chlorine in situ. A side reaction is subsequent addition of hypochlorous acid, which proceeds under the influence of excess chlorine. It is convenient to use tert-butyl hypochlorite for the chlorination of more reactive arylisoxazoles.See [1] for communication XXV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1325–1328, October, 1973.