Process for synthesizing O-diphenylphosphinolbenzoic acid

Abstract

The invention relates to a synthetic method of o-diphenylphosphinolbenzoic acid. The synthetic method comprises the following steps: taking chlorodiphenylphosphine as a starting material, adding the chlorodiphenylphosphine and an alkali metal to a solvent for cracking to generate diphenylphosphine alkali salt, then adding ortho-chlorobenzoate or ortho-chlorobenzoic acid ether for reaction to generate diphenylphosphine benzoate or diphenylphosphine benzoic ether, and obtaining the o-diphenylphosphinolbenzoic acid after hydrolysis. The solvent is tetrahydrofuran, 2-methyltetrahydrofuran or an ether solvent such as n-butyl ether or 1,4-dioxane and the like, the alkali metal for cracking can be lithium, sodium or potassium, the ortho-chlorobenzoate can be lithium ortho-chlorobenzoate, sodium ortho-chlorobenzoate and lithium ortho-chlorobenzoate, and the ortho-chlorobenzoic acid ether can be ortho-chlorobenzoic methyl ester, ortho-chlorobenzoic acid ethyl ester, ortho-chlorobenzoic acid propyl ester, ortho-chlorobenzoic acid butyl ester, ortho-chlorobenzoic acid pentyl ester and the like. The synthetic method can prepare the o-diphenylphosphinolbenzoic acid above 0 DEG C at normal pressure with safe and stable operation, can save a large amount of energy sources and is suitable for large-scale production.

Description

technical field [0001] The invention relates to a method for synthesizing O-diphenylphosphinebenzoic acid. Background technique [0002] O-diphenylphosphine benzoic acid is a bidentate hybrid water-soluble organic phosphine-type water-soluble phosphine ligand, which can form a complex with transition metal elements such as rhodium and nickel as a catalyst for a homogeneous reaction. The design of water-soluble phosphine-ligand catalysts can solve a core problem of homogeneous complex catalysts: that is, the separation of transition metal catalysts from products and the recycling of catalysts. In the 1970s, the famous SHOP method successfully used nickel P-O bidentate complexes to catalyze ethylene oligomerization into α-olefins. The reaction conditions were mild and the raw materials could be completely converted into useful products. The problem of difficult separation of catalyst and product has created a successful precedent for homogeneous catalysis and multiphase, whic...

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Problems solved by technology

However, the reaction conditions are very harsh. This kind of absolute low temperature is difficult to operate in process production. A large amount of volatilized liquid ammonia will cause great pollution to the environment and bring serious injuries to the workers on site. Large-scale industrial production is almost impossible.

In recent years, Stadler (Org.Lett., 2002, 4(20), 3541-3543) etc. have adopted a catalytic method to catalyze HPPh with Pd catalyst 2 Synthesizing O-diphenylphosphinebenzoic acid with O-iodobenzoic acid at 180 ° C, not only the raw materials are expensive, but also the yield is only 26%, resulting in high product cost

In addition, HPPh 2 It is very easy to oxidize and even spontaneously ignite in the industrial production process, and the production is relatively dangerous. This process route is not competitive for the industrial production of O-diphenylphosphine benzoic acid

Guo Mengping (Journal of Yichun University (Natural Science), 2007, 29(4), 12) and others reported a PPh cracking method with lithium metal under the condition of 20±2℃. 3 process, but when we repeatedly check this route, it is difficult to reach the 50% yield reported in the literature

And, when O-chlorobenzoic acid adding speed is slower, the impurity of production is very much, and yield is extremely low

If it is quickly added to the reaction system, the temperature will rise sharply, the operation controllability will be poor, and it will easily cause material flushing, which will pose a great safety hazard

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