METHOD FOR SELECTIVE PREPARATION OF EXO,EXO- AND ENDO,ENDO-DI(2-ETHYLHEXYL)NORBORNENE-2,3-DICARBOXYLATES FROM C5 FRACTION OF LIQUID PYROLYSIS PRODUCTS Russian patent published in 2021 - IPC C07C67/347 C07C69/753 

FIELD: chemical industry.

SUBSTANCE: invention relates to a method for the selective production of endo,endo-di(2-ethylhexyl)norbornene-2,3-dicarboxylate or a mixture of exo,exo- and endo,endo-di(2-ethylhexyl)norbornene-2,3-dicarboxylates, where the target compounds are obtained using a by-product of the production process: C5 fraction of liquid pyrolysis products, at the same time, at the first stage, endo-endic anhydride (EA) is obtained by a selective reaction of maleic anhydride (MA) with cyclopentadiene (CPD) contained in the C5 fraction of the LPP, for which finely ground MA is added in portions to the C5 fraction in a molar ratio of CPD:MA=1.00-1.10:1 when cooled so that the temperature of the reaction mass does not exceed 40°C, it is kept under stirring and at a temperature no higher than 40°C until the maleic anhydride is completely consumed, the reaction mass is diluted with 2-ethylhexanol (2-EH) in an amount of 60-65, wt. %, from the calculated one, the unreacted part of the C5 fraction is distilled at a temperature of 30-50°C, the remaining part of 2-EH is added to the reaction mass cubed and at the second stage, EA is esterified with 2-ethylhexanol either at a temperature of 120-157°C in toluene medium in the presence of an acid catalyst for the synthesis of endo,endo-di(2-ethylhexyl)norbornene-2,3-dicarboxylate, or at a temperature of 155-220°C without a solvent in the presence of an amphoteric catalyst for the synthesis of a mixture of endo,endo- and exo, exo-di(2-ethylhexyl)norbornene-2,3-dicarboxylates. The esters obtained can be used as monomers in the reaction of metathesis polymerization with the opening of the cycle, and also as an oil-phosphate plasticizer of PVC.

EFFECT: processable and simple method for the selective production of endo, endo - and exo, exo-di(2-ethylhexyl)norbornene-2,3-dicarboxylates based on available raw materials: C5 fractions of liquid pyrolysis products and maleic anhydride.

3 cl, 2 ex