Potassium persulfate, reaction with phenols

Reactions with persulfate and pyrosulfate. The persulfate (peroxy-dlsulfate Ion, S2O8 ) reaction, also known as the Elba persulfate oxidation, has been Important In synthesis of hydroxylated phenols. The method has occasionally been used for synthesis of 0-sulfate conjugates. For example, 4-hydroxy-2-nltrophenyl sulfate was obtained when 3-nltrophenolate was stirred with potassium peroxydlsulfate at room temperature for 2 days (91,). The persulfate reaction has been used for the sulfation of various phenols and aromatic amines however the yields are usually low to moderate (77 ). The sulfate group Is preferentially Introduced In the 4-posltlon of phenols and In the 2-posltlon of aromatic amines but If these positions are blocked substitution at the 2- and... 

When aromatic amines react with potassium persulfate in alkaline aqueous solution at room temperature in the absence of a catalyst, they are converted to the corresponding phenol . Behrman has studied the ortho-para ratio in this reaction and found that the ortho product predominates over the para product (in contrast with the Elbs reaction)... 

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