Chloric acid, oxidation phenols

A detailed study ot the oxidation of ortho-, meta-, and para-tnfluoromethyl phenols showed that oxidation with chloric acid at 5 to 10 C for 0 5 h gives a complex mixmre of products [59] with isolable 2-chloro-1 hydroxy-2-tnfluoro-methylcyclopent-4-en-3-one-1 -carboxylic acid... 

Phenols with a trifluoromethyl substituent on the ring are hydroxylated with potassium persulfate,167 while oxidation with chloric acid causes oxidation to quinonc and ring contraction together with incorporation of chlorine in the product.176 A detailed study of the oxidations of 2-, 3-, and 4-(trifluoromethyl)phenols shows that the oxidation with chloric acid at 5 to 10°C for 0.5 hours gives complex mixtures of products 1 77 5-chloro-l-hydroxy-4-oxo-5-(tri-fluoromethyl)cyclopent-2-enecarboxylic acid (12) being isolated as the major product from the 2-isomer. 

Fluonnatedphenols are usually oxidized to cyclohexadienone and benzoqui-none derivatives and to products of ring rearrangement and ring degradation Phenols with a tnfluoromethyl group at the nng are hydroxylated by potassium persulfate [57], whereas chloric acid causes oxidation to quinone, mg contraction, and incorporation of chlorine in the product [58] (equation 53)... 

---