| 摘要 |
A method is described for the simultaneous preparation of 4-bromophenols and p-benzoquinones, intermediates useful in the preparation of hydroquinones and 4,4'-dihydroxybiphenyls respectively. Hydroquinones and 4,4'-dihydroxybiphenyls are useful monomers for the preparation of a variety of polymers. In one example phenol is reacted with in the presence of HBr, a catalytic amount of cupric bromide and a stoichiometric excess of oxygen under relatively mild conditions to provide a mixture of the phenol, 4-bromophenol, and 1,4-benzoquinone. Phenol conversion was 54 percent and selectivities for bromophenol and benzoquinone were 23% and 37% respectively. Limiting the amount of HBr present in the reaction mixture was shown to control the amount of benzoquinone produced.
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