The Synthesis of Catechol, Resorcinol and Hydroquinone

All the methods for the industrial synthesis of phenol with the exception of 

The alkaline fusion of aryl 1,3-disulphonates and the acidic rearrangement of 

3- and 1,4-bis-hydroperoxides of dialkylbenzenes are important methods for the production of the corresponding dihydric phenols. 

Unlike the almost abandoned route for phenol from benzenesuiphonic acid by alkaline fusion, resorcinol is manufactured substantially by this methodology which was first described in 1878. The yield of resorcinol on benzene-1,3-disulphonic acid is 94% (ref.29) after recovery from the acidified alkaline solution and purification by distillation. For catechol, the hydrolysis of 

2-chtorophenol, originally an important route, was effected with a 300% molar excess of alkali at 190 C in the presence of a copper catalyst (usually a copper vessel). In the absence of copper the product contained a high proportion of resorcinol formed by the involvement of an aryne intermediate. For both resorcinol and for hydroquinone, the bis-hydroperoxidation of 1,3- and 

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