METHOD FOR PRODUCTION OF ORTHO- AND PARA-AMINOPHENOLS Russian patent published in 2022 - IPC C07C213/00 C07C215/76 B01J31/22 

FIELD: organic chemistry.

SUBSTANCE: invention relates to organic chemistry, specifically to a method for the production of ortho- and para-aminophenols, which are important raw materials for chemical and pharmaceutical industries. The proposed method for the production of ortho- and para-aminophenols is carried out by oxidation of aniline in an alkaline medium. The method includes isolation of intermediate 4(2)-aminophenylsulfates by extraction with butanol and their hydrolysis with hydrochloric acid at 85-95°C. Aniline oxidation is carried out with ammonia persulfate (hereinafter – APS), at a molar ratio of aniline : NaOH : APS equal to 1:5:2, a temperature of 40-60°C, in the presence of 0.01-0.03 wt.% of a phthalocyanine oxidation catalyst (phthalocyanine of cobalt, iron (II), iron (III), manganese, nickel, zinc), for 3-15 h, to intermediate 4(2)-aminophenylsulfates. Then, the reaction mixture is cooled to a room temperature, intermediate 4(2)-aminophenylsulfates are isolated by extraction with butanol, which are subjected to acidic hydrolysis to obtain a mixture of ortho- and para-aminophenols, from which ortho-aminophenol is isolated by extraction with chloroform, para-aminophenol remains in an aqueous phase.

EFFECT: increase in the yield of target products.

2 cl, 1 tbl, 26 ex