METHOD OF PRODUCING HIGHLY PURE PENTAERYTHRITOL TETRA-2,2-DIMETHYLBUTANOATE Russian patent published in 2025 - IPC C07C67/08 C07B41/12 C07C69/33 

FIELD: organic chemistry.

SUBSTANCE: invention relates to organic chemistry, specifically to a method for synthesis of highly pure pentaerythritol tetra-2,2-dimethylbutanoate, which is a promising additive for synthetic lubricating oil. Method is carried out by catalytic esterification of 2,2-dimethylbutyric acid with pentaerythritol in the presence of methanesulphonic acid, with molar ratio of pentaerythritol to carboxylic acid of 1:6, in a stream of nitrogen at 110-130 °C, for 6-8 hours. Method is characterized by that reaction is carried out in a medium with weight content of sulfolane 30 wt.%, extraction of end product is carried out by water deposition, after filtration, the precipitated crystals are subjected to vacuum drying and the obtained mother solution after evaporating water is used as recycle.

EFFECT: improved method of producing the desired tetraether in mild conditions with output of 96-98% and purity higher than 99%.

1 cl, 3 ex