- Studies in Oxidation of 1-(2'-Hydroxyphenoxy)-2-naphthol, 2-(2039-Hydroxyphenoxy)-1-naphthol and Related Oxydiphenols
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Oxidation of 1-(2'-hydroxytetrachlorophenoxy)-2-naphthol (IIIa), 1-(2' hydroxyphenoxy)-2-naphthol (IIIb), 2-(2'-hydroxytetachlorophenoxy)-1-naphthol (Va) and 2-(2'-hydroxyphenoxy)-1-naphthol (Vb) by various non-quinone oxidants and a few quinone oxidants like tetrachloro-o-benzochinone (o-chloranil), tetrabromo-o-benzochinone (o-bromanil) and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) have been studied.Among the non-quinone oxidants like manganese dioxide, ferrie chloride, potassium hexacyanoferrate (III), potassium hypobromite and (diacetoxyiodo)benzene, used in the oxidation of oxydiphenols (IIIa, Va and IIIb) only manganese dioxide brings about rearrangement in the case of IIIa and IIIb.In the other cases, only the normal oxidation products are obtained.The quinone oxidants bring about rearrangement to a considerable extent to yield dienones.Formation of unusual products (Ia and IIa) in the oxidation of IIIb and IIa from Vb with o-chloranil, has been explained on the basis of the intermediacy of the quinol ethers VII and VIII respectively.Also change of solvent from benzene to more polar solvents in the case of quinone oxidation does not favour rearrangement and reduces the overall yield.
- Kasturi, T. R.,Prasad, K. B. Ganesha,Rajashekar, B.
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p. 813 - 818
(2007/10/02)
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