Reaction LXXXIV.—Addition of Phenols to Quinones

Reaction LXXXIV. Addition of Phenols to Quinones. (A., 200, 251 215,134 B., 24,1341.)—Quinones readily react with 1 mol. of p-di-hydric phenols and 2 mols. of other phenols to form the highly coloured ether compounds, quinhydrones and phenoquinones respectively. 

Quinhydrone can be prepared from quinone or quinol by partial reduction or oxidation respectively (see Preparation 154). 

Method I.—10 gms. (1 mol.) of quinone and 10 gms. (1 mol.) of quinol are separately dissolved in the minimum quantity of water, and the solutions mixed and warmed. After cooling, the precipitate is filtered off and washed with water. 

—Almost theoretical (10 gms.). Lustrous green prisms or leaflets quinone-like odour soluble in warm petroleum ether insoluble in cold water M.P. 171°. (B 24, 1341 28, 1615.) 

20 gms. (1 mol.) of phenol and 12 gms. (1 mol.) of quinone are dissolved in petroleum ether or benzene and refluxed for 10 minutes. The solution is then concentrated on a water bath until crystals separate on cooling. They are filtered off and washed in water. 

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