Potassium chlorate and hydrochloric acid oxidize phenol, salicylic acid (o-oxybenzoic acid), and gallic acid ([2.3.4] trioxybenzoic acid) to tri chlorpyroracemic acid (isotrichlorglyceric acid), CC13 C(OH)2 C02H, a substance also obtained from trichloracetonitrile, CC1 3 CO CN, by hydrolysis.
Their alkyl derivatives readily oxidize to pyrazine carboxylic acids.
Manganese dioxide and dilute sulphuric acid oxidize it to quinone.
The second process is one patented by Fritz Ullmann of Geneva, who utilizes chromic acid to oxidize the phosphuretted and sulphuretted hydrogen and absorb the ammonia, and this method of purification has proved the most successful in practice, the chromic acid being absorbed by kieselgiihr and the material sold under the name of "Heratol."
Potassium bichromate and sulphuric acid oxidize it to carbon dioxide and acetic acid, while alkaline potassium permanganate oxidizes it to carbon dioxide.
