METHOD OF PRODUCING 2-ISOPROPYL-P-XYLENE AND 2,5-DIISOPROPYL-P-XYLENE Russian patent published in 2011 - IPC C07C15/107 C07C15/02 C07C2/68 C07C2/70 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing 2-isopropyl-p-xylene and 2,5-diisopropyl-p-xylene through alkylation of p-xylene with propylene in liquid phase, characterised by that p-xylene undergoes alkylation at temperature 70-90°C, and at the first step alkylation is carried out in the presence of a AlCl₃ catalyst until achieving 40-90% conversion of the initial hydrocarbon and accumulation of 30-50% mono-isopropyl-p-xylene in the alkylate. Further, 5-mono-isopropyl-p-xylene undergoes alkylation at the second step in the presence of AlCl₂H₂PO₄ such that, after achieving total content of isomers 2,5-, 2,3-, 2,6-di-isopropyl-p-xylene of 30-50% in the alkylate, supply of propylene is cut and the obtained alkylate is held at temperature 70-90°C for 2-6 hours until achieving at least 95% concentration of 2,5-di-isopropyl-p-xylene and then extracting the end product using known techniques.

EFFECT: engineering solution simplifies production of mono-isopropyl-p-xylene and 2,5-diisopropyl-p-xylene and increases output of end products.

1 cl, 7 ex, 1 tbl, 1 dwg