METHOD OF PRODUCING 2-ETHYLHEXANOIC ACID Russian patent published in 2011 - IPC C07C53/128 C07C51/02 

FIELD: chemistry.

SUBSTANCE: method of producing 2-ethylhexanoic acid from production wastes of N-2-ethylhexyl-N'-phenyl-n-phenylenediamine involves alkylation of n-aminodiphenylamine with an alcoholic solution of potassium alcoholate in 2-ethylhexanol, treating the aqueous waste layer of the alkylation reaction with mineral acids from a group comprising sulphuric or phosphoric acid to pH 2-4 with release of 2-ethylhexanoic acid, in which after alkylation, the reaction mass is treated with water, cooled to 70-90°C, 2-ethylhexanol or aliphatic solvent or mixture of aliphatic solvents with boiling point between 70 and 120°C is further added in amount of 2-25; 20-80 or 25-55 wt % of the reaction mass, respectively. The obtained mixture is kept at 70-90°C, settled and layered into an aqueous and organic layer. The organic layer is additionally washed with water while stirring, settled and layered, and aliphatic solvents or mixture thereof and 2-ethylhexanol are successively distilled off from the said layer at normal pressure and under a vacuum, respectively. N-2-ethylhexyl-N'-phenyl-n-phenylenediamine is extracted and the remaining aqueous waste layers are merged, neutralised with mineral acids, and 2-ethylhexanoic acid is extracted from the organic layer formed during layering after neutralisation.

EFFECT: high quality of 2-ethylhexanoic acid owing to low content of traces of amine-containing impurities and low environmental pollution due to low residual wastes.

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