METHOD OF PRODUCING PARA-AMINOBENZOIC ACID

摘要

FIELD: chemistry.SUBSTANCE: invention relates to a method of producing para-aminobenzoic acid. Method is realised by neutralising para-nitrobenzoic acid with an inorganic base with subsequent reduction of neutralised para-nitrobenzoic acid with hydrazine hydrate in presence of catalyst at temperature 95-100 °C with further filtration of reaction mass and separation of para-aminobenzoic acid. Method is characterised by that reduction is carried out in an aqueous medium for 15-30 minutes in presence of 5-15 wt% of weight of para-nitrobenzoic acid of hexahydrate iron (III) chloride as catalyst in molar ratio of para-nitrobenzoic acid, inorganic base, hydrazine hydrate and water equal to 1: (1.0-1.5):(3.5-4.5):(45.0-55.0).EFFECT: proposed method reduces duration of reaction and improves safety of process while maintaining high output of para-aminobenzoic acid.1 cl, 1 tbl, 15 ex