METHOD FOR OBTAINING ORTHO- AND PARA-AMINOPHENOLS Russian patent published in 2023 - IPC C07C215/76 C07C213/00 C07B61/00 C07B45/00 C01B15/08 

FIELD: organic chemistry.

SUBSTANCE: invention relates to the synthesis of ortho- and para-aminophenols, which are important raw materials for the chemical and pharmaceutical industries. The invention relates to organic chemistry, specifically to the synthesis of 4- and 2-aminophenols, which are important raw materials for the chemical and pharmaceutical industries. The method for obtaining ortho- and para-aminophenols by oxidizing aniline in an alkaline medium and subsequent hydrolysis of intermediate 4(2)-aminophenyl sulfates with hydrochloric acid at 85–95°C is characterized by the fact that the synthesis of target ortho- and para-aminophenols is carried out without isolation of intermediate 4 (2)-aminophenyl sulfates. To increase the yield of target products, the process of oxidation of aniline with ammonium persulfate (PSA) or sodium (PSN) or potassium (PSK) is carried out at a molar ratio of Aniline:NaOH:PSA (PSK, PSN) equal to 1:5:1.5 at 40-50°C for 2–15 hours with continuous air bubbling of the reaction mixture, from which ortho-aminophenol is isolated by extraction with chloroform, and para-aminophenol remains in the aqueous phase.

EFFECT: increasing the yield of target products.

1 cl, 4 tbl, 1 ex