METHOD FOR MODIFICATION OF SILICA GEL SURFACE WITH 3,5-DI-TERTIARY-BUTYL-1,2- BENZOQUINONE Russian patent published in 2003 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention describes method for modification of silica gel surface with 3,5-di-tert.-1,2-benzoquinone. Method involves alkylation of 3,5-di-tert.-butyl-1,2-dihydroxybenzene with allyl bromide in acetone medium in the presence of excess of anhydrous potash, distillation and Kleisen's rearrangement followed by hydroxylation of obtained compound with triethoxysilane in the presence of paramagnetic complex of platinum π-allyl-2,4,6,8-tetra-tert.-butyl- 1-hydroxyphenoxazinolate as a catalyst [1] in pentane medium for 5 min under inert atmosphere and addition of reaction product without its further purification to co-condensation with silica gel grains of sort LSL₂₅₄ 5/40 and tetraethoxysilane. Then method involves oxidation of prepared silica gel modified with 3,5-di-tert.-butyl- 1,2-dihydroxybenzene by side chain to silica gel modified with 3,5-di-tert.-butyl-1,2-benzoquinone by effect with nitric acid. Kleisen's rearrangement after alkylation stage is carried out by keeping reaction mass in system CH₂Cl₂/TiCl₄ for 45-60 min under inert atmosphere. EFFECT: increased yield of ready product at alkylation stage.