A kind of preparation method of gamma-substituted hexadienoic acid

Abstract

The invention relates to a preparation method of γ-substituted hexadienoic acid, which is characterized in that: (1) at 10-40°C, add a solvent, a catalyst, and a catalyst assistant to a reaction vessel, stir, and introduce oxygen, and add 1-( 2-furyl)-1-alkylcarbinol, control catalyst: catalytic promoter: the molar ratio of 1-(2-furyl)-1-alkylcarbinol is 0.0001~5:0.0001~3:100, and the reaction temperature is 0~200℃, pressure 0.1~20MPa, reaction 1~74h; solvent is a mixture of water phase and organic phase with a volume ratio of 1:0.01~3, the water phase is a phosphate acid solution, and the organic phase is a reaction inert solvent , the catalyst is a palladium compound, and the catalytic assistant is an amine or a phosphine compound; (2) cooling the reaction vessel to room temperature, adding an organic solvent for extraction, and performing vacuum distillation on the organic phase. The invention has the advantages of avoiding technical and economic disadvantages in the existing synthetic route, simplifying the technological process, reducing consumption and emission, reducing energy consumption and cost, and being suitable for industrialized production with expanded production capacity.

Description

technical field [0001] The invention belongs to the field of fine chemical preparation, and relates to a method for preparing gamma-substituted hexadienoic acid by catalytic oxidation of 1-(2-furyl)-1-alkylmethanol as a raw material. Background technique [0002] 2,4-Hexadienoic acid, commonly known as sorbic acid, molecular formula CH 3 -CH=CH-CH=CH-COOH, the molecular structure contains a carboxyl group and a conjugated double bond, the carboxyl group makes it more acidic and can inhibit the growth of microorganisms; the conjugated double bond can be combined with the sulfhydryl group of the microbial enzyme (pH< 6), thereby destroying the structure of the enzyme system, inactivating the enzyme, and finally inhibiting the reproduction of microorganisms to achieve the antiseptic and fresh-keeping effect. Therefore, sorbic acid and its sodium salt and potassium salt are a new type of food additive, which can inhibit the growth of bacteria, molds, yeasts, etc., with remar...

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Problems solved by technology

[0007] 4) Crotonaldehyde and acetaldehyde condensation method, that is, crotonaldehyde and acetaldehyde are condensed under the action of dilute alkali to obtain sorbaldehyde, and sorbaldehyde is oxidized with oxygen under the action of silver oxide to obtain sorbic acid. There are many side reactions, and the products are complex and difficult to separate. low yield;

[0011] Although some of these process routes have been industrialized, the common disadvantages are low yield, many side reactions, and more pollution of three wastes. Some process routes have long process flow, complicated operation, rare raw materials, and some raw materials and intermediates are toxic.

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