Triphenylphosphine, molecular formula c18h15p, molecular weight 262.30. Which is a white to off white crystalline powder; It is easily soluble in alcohol, benzene and trichloromethane and insoluble in water. Triphenylphosphine is an important ligand of homogeneous catalyst used in petrochemical and fine chemical production, and its new uses are constantly developed, and the demand is increasing year by year.
Triphenylphosphine is a triphenyl substituent of phosphine, which is mainly reductive and nucleophilic. Its application fields are as follows:
1. Important ligand of homogeneous catalyst used in petrochemical and fine chemical production.
2. Basic raw material of rhodium phosphine complex catalyst.
3. It plays an important role in the synthesis of vitamin D2, vitamin A, chlorpromycin and other drugs and plant pigments.
4. Brighteners, heat stabilizers, light stabilizers, antioxidants, flame retardants, antistatic agents, rubber anti ozone agents and analytical reagents in the dye industry.
5. Triphenylphosphine is widely used in the chemical industry. It is an important catalyst for the synthesis of fine chemicals. Through technical improvement, new petroleum processing catalysts can be better applied; New biocatalysis technology and catalyst; New and efficient catalysts for environmental protection; New catalysts for organic synthesis; New high efficiency catalysts for polyolefins; New materials for catalyst support and various new catalytic promoter materials; It can also be used as functional fine chemicals and new paper-making special chemicals; New oilfield chemicals suitable for protective exploitation and enhanced oil recovery; New surfactants; High Performance Waterborne functional coatings and additives; New textile dyeing and finishing auxiliaries; High performance environmental friendly adhesive; New safety and environmental protection pigments and dyes; High performance environmental friendly leather chemicals. Triphenylphosphine can also be used as an important chemical product for chemical synthesis, such as β- Intermediates in the synthesis of carotene, cefprozil and cefdinir.
Triphenylphosphine is an important ligand of homogeneous catalysts used in modern petrochemical and fine chemical production, such as Wilkinson catalysts for homogeneous catalytic hydrogenation of olefins and vistamoxin reagents used in fine chemical industry, which are widely used. The synthesis of triphenylphosphine has long been reported in the literature. There are three main methods:
(1) Grignard reagent method;
(2) Triphenylphosphine oxide reduction method;
(3) Sodium method.
As early as 1882, Michaelis reported that sodium, bromobenzene Phosphorus trichloride is used to prepare triphenylphosphine from ether ", but the backward sodium sand production technology and the use of ether in the early stage limited the application and development of the sodium method. From the literature reports, it can be seen that the main research work was concentrated after 1960. In the 1960s and 1970s, the Grignard method and the sodium method were the main research work, and 14 patents were reported. Since the 1980s, the research work is mainly the sodium method and the triphenylphosphine oxide reduction method, and 17 patents were reported.
Compare three methods:
Grignard process: it has been used in large-scale production for a long time. Although the yield has been improved to 76% - 91% by dodonov and others, it is not ideal due to the large loss of solvent tetrahydrofuran, high price and long cycle, and the large loss of operation complex agent tetrahydrofuran, high price and long cycle.
Triphenylphosphine oxide reduction method: the research started from the reuse of waste catalyst and gradually increased, but the price of reducing agents used, such as R3a l.naa ih4 + a ICL3, clsih, S + Pd / C and so on, is relatively high. If it is used in industrial production, the cost is still very high, and it can not meet the growing triphenylphosphine market.
Sodium method: the raw materials used are metal sodium, halogenated benzene, phosphorus trihalide, and the solvents are toluene, butyl ether, benzene, diethyl ether, etc. the yields reported in the literature are 44% ~ 95%. In contrast, sodium method has the advantages of low cost, short reaction cycle and simple operation. With the development of sodium sand production technology at home and abroad.
The improvement of the technique has a very good development prospect, and it is estimated that it will replace Grignard's method in the dominant position.
There are two ways to prepare triphenylphosphine by sodium method:
One is the one-step reaction of the mixture of sodium, chlorobenzene and phosphorus trichloride, which requires catalytic initiation;
The other way is that sodium and chlorobenzene first make sodium benzene, and then react with phosphorus trichloride to make triphenylphosphine.
On the premise of selecting a good catalyst, the former method has more advantages. It not only has a short cycle and simple steps, but also can avoid the impact of the loss of highly active sodium benzene.
Up to now, there are few reports on one-step synthesis, and all of them are patents. Triphenylphosphine and dichlorotriphenylphosphine are selected as catalysts, and the yield is less than 93%. We selected dibromotriphenyl phosphine, which has not been reported in the literature, as the catalyst, and selected the low-cost sodium method to synthesize triphenyl phosphine in one step, and obtained ideal results with a yield of 92.4%. At the same time, the preparation of triphenylphosphine with dibromotryphenylphosphine as catalyst is an ideal synthetic route with low cost It is characterized by low cost, simple operation, high yield and pure product. The initiation control of the reaction is better than that of triphenylphosphine and dichlorotriphenylphosphine. The optimum reaction conditions are: reaction temperature 30 ~ 40 ° C; The material ratio Na "PHC l.pcl is 6.1.3. * 1, the reaction initiation temperature is 50 ~ 60 ° C, and the average diameter of sodium sand is preferably less than 40 μ m。 It should meet the catalytic grade index, but pretreatment before reaction is essential. The average yield was 80.15% and the purity was > 99%.