Synthetic method for beta-carotene

Abstract

The invention provides a synthetic method for beta-carotene. The synthetic method comprises the following steps: preparing an organic phosphine salt from retinol or a derivative thereof; and subjecting the organic phosphine salt to an intermolecular oxidative coupling reaction in an oxygen atmosphere in the presence of a vanadium compound catalyst and a molecular sieve so as to obtain beta-carotene. According to the invention, clean, environment-friendly, economic, easily-available, convenient, safe and oxygen-containing gas is used as an oxidizing agent, so no harm is posed to environment, cost is low, and industrial production is facilitated; a vanadium compound is used as a catalyst, so time for the coupling reaction is greatly reduced; the molecular sieve is used as a cocatalyst, so the usage amount of the catalyst is lowered, catalytic oxidation effect is improved, and discharge of waste water containing metal ions is reduced; the addition of a polyether phase-transfer catalyst can initiate a reaction of substrates in a heterogeneous-phase reaction system; and a solid alkaline compound forms a complex with the polyether phase-transfer catalyst, and is thus dissolved in an organic phase and participates in the reaction, so the solubility of alkali in the organic phase is effectively controlled, the reaction is promoted, production of by-products is inhibited at the same time, the yield of the target product is increased, and thus, the purpose of improving yield is achieved.

Description

technical field [0001] The present invention relates to beta-carotene, in particular to a synthesis method of beta-carotene. Background technique [0002] β-carotene is a source of vitamin A, which can be used in medicine, food, cosmetics, feed additives, and dyes, and has a good market prospect. [0003] There are many domestic research reports on the synthesis of β-carotene. According to different reaction routes, the synthesis routes of β-carotene can be divided into C19+C2+C19, C15+C10+C15 and C20+C20 condensation reactions. Among them, the organic phosphonium salt obtained by the reaction of vitamin A alcohol or its derivatives with triphenylphosphine is an important intermediate of β-carotene, which can further undergo C20+C20Wittig condensation reaction to prepare β-carotene, and can also be used in the presence of oxidants In the presence of self-intermolecular oxidative coupling reaction to prepare β-carotene; [0004] Wittig condensation reaction route: the organ...

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Problems solved by technology

[0009] Oxygen is a recognized green oxidant, and the reaction product is water, which has the advantages of being economical, practical and environmentally friendly. The prior art has reported the application of oxygen in the oxidative coupling reaction of vitamin A organic phosphine salts, but according to the existing research results It shows that molecular oxygen as an oxidant in the above coupling reaction not only has a slow reaction rate but also a low product yield, and sometimes even does not react.

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