Process for preparing ketoisophorone

Abstract

This invention relates to a method for producing oxo-isophorone. It comprises raw material beta-isophorone, organic base, assisting solvent, schiff bases and their derivatives with arginine as primary structure, and transient metal-organic ligand composed transition metal halide as catalyst, where the mole ratio of raw material beta-isophorone and transition metal halide is between 2000:1 and 20:1, and the mole ratio of raw material beta-isophorone and organic bases is 50:1 and 2:1, with reaction temperature between -30 and 150Deg C, and the oxo-isophorone is produced by oxidation using molecular oxygen or oxygen rich gas.

Description

technical field [0001] The invention relates to a preparation method of oxyisophorone. The method is to oxidize raw material β-isophorone with molecular oxygen or oxygen-enriched gas in the presence of an organic base and a cosolvent to generate oxoisophorone . The catalyst used therein is a transition metal-organic ligand catalytic system composed of arginine-based Schiff base and its derivatives and transition metal halides. Background technique [0002] Oxyisophorone is an important chemical and pharmaceutical intermediate, which can be used as a flavoring agent or fragrance in food additives, and can also be used in the synthesis of cosmetics. Oxyisophorone is also an important intermediate for the preparation of vitamins and carotenoids. [0003] Due to the importance of oxyisophorone in chemical and pharmaceutical fields, the oxidation of α-isophorone or β-isophorone to oxyisophorone has long been a research topic in the field of chemical engineering. hotspot. Espe...

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Problems solved by technology

[0005] In US 4046813, a kind of acetylacetone complexes of lead, vanadium, chromium, manganese, iron, cobalt, etc. are used as catalysts to prepare oxoisophorone by catalytic oxidation of β-isophorone in the presence of organic base pyridine. The method of ketone, although the method has about 100% conversion rate, but simultaneously the reaction also easily makes β-isophorone isomerize to α-isophorone, and high polymeric by-products are easily formed in the reaction, Therefore, the selectivity of the reaction decreases

[0006] In US6297404 and US6300521, a method for preparing oxoisophorone by catalytic oxidation of β-isophorone using a catalytic system of Schiff base and lithium acetate or ammonium acetate in the presence of DMF or DMA and tripropylamine is described , one of the biggest disadvantages of this method is that the reaction is prone to produce 3,5,5-trimethyl-cyclohex-2-ene-4-hydroxyl-1-one, 2,2,6-trimethylcyclohexane-1 , 4-diketone and other by-products, because the molecular weight and properties of these by-products are similar to the product, so it is quite difficult to separate them from oxyisophorone

[0007] And in US4898985, described a kind of in the presence of triethylamine and ethylene glycol dimethyl ether, use the porphyrin or phthalocyanine complex of iron, cobalt, ketone, manganese as catalyst, catalytic oxidation β-isophorone The m

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