METHOD OF PRODUCING PARA-AMINOBENZOIC ACID Russian patent published in 2016 - IPC C07C227/04 C07C229/60 

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 a heterogeneous catalyst at temperature of 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 1-1.5 hours in presence of 0.8-2.0 wt% of weight of para-nitrobenzoic acid of nickel-aluminium alloy powder (Ni = 48.0-53.0 wt%, Al = 47.0-52.0 wt%) as catalyst in molar ratio of para-nitrobenzoic acid, inorganic base, hydrazine hydrate and water, equal to 1:(1.5-2.0):(3.5-4.5):(45.0-55.0).

EFFECT: disclosed method reduces duration of reaction and increases safety while maintaining high output of para-aminobenzoic acid.

1 cl, 1 tbl, 15 ex