PROCESS FOR JOINT PREPARATION OF PYROCATECHOL AND HYDROQUINONE Russian patent published in 1995 - IPC

FIELD: preparation of organic compounds. SUBSTANCE: preparation is carried out from phenol and an aqueous solution of hydrogen peroxide at a molar ratio of 1:(0.4-1.5) in the presence of ferrous sulfate at 40 to 101 C in a direct flow of reagents in a freely dripping film of reaction mixture on a packing in a column-type apparatus and in a counterflow of the gas phase in the form of water and phenol vapors and evolving oxygen. Reagent and catalyst solutions are fed continuously to the column top, vapors are condensed and recycled to the column as a reflux, and the reaction mixture is withdrawn from the column bottom through a hydraulic lock. EFFECT: improved phenol selectivity and simpler technology. 1 tbl