METHOD OF PRODUCING 2,2-BIS-(CARBOXY)-1,3-PROPANEDICARBOXYLIC ACID BY OXIDATION OF PENTAERYTHRITOL Russian patent published in 2013 - IPC C07C51/295 C07C55/24 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing 2,2-bis-(carboxy)-1,3-propanedicarboxylic acid (methane-tetracarboxylic acid, MTCA). The method is realised by oxidising pentaerythritol with potassium permanganate solution, taken in molar ratio of potassium permanganate to pentaerythritol of (6.4-6.6):1, in a medium of potassium carbonate at temperature of 65-70°C for 4-5 hours and held at temperature of 20-25°C for 8-10 hours; excess oxidant is removed by adding oxalic acid. The obtained mixture is filtered to separate the residue; the filtrate is evaporated; the evaporated solution is neutralised with hydrochloric acid to obtain carboxylic acid. The end product is separated by crystallisation and filtration at temperature of 0°C.

EFFECT: high output of the end product.

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