Triphenylphosphine reacts vigorously with oxidizing materials. .
This product is colorless to pale yellow monoclinic crystal below the room temperature, colorless to pale yellow transparent oily liquid above the room temperature with skin irritation and a pungent odour. Its mp about 22 ℃and bp 360 ℃(0.1 MPa) , n25D of 1.589 and relative density of 1.184 (20 ℃). And it is miscible with alcohol, ether, benzene and acetone and other organic solvents, while insoluble in water.
In this preparation method, phenol and phosphorus trichloride was used as raw materials. After esterification and vacuum distillation, the product namely triphenyl phosphite can be obtained.
3C6H5OH + PCl3 [15~20 ℃] → (C3H5O) 3P + 3HCl
Specific process can be classified into batch and continuous processes.
(1) Batch process
The phenol was added into the reactor, after warming to melt phosphorus trichloride was added to react with phenol at 70~90 ℃. After the phosphorus trichloride addition was completed, the temperature of reaction mixture was raised to about 150 ℃. After the removal of hydrogen chloride and unreacted phenol dissolved under reduced pressure at a high temperature, the product can be achieved.
(2) The use of a tower reactor
Phenol was feeding under the condenser located in the upper portion of the tower, while phosphorus trichloride enters above the receptacle located in the lower portion of the tower. Both reacted in the tower, and the product was collected in the receiver, meanwhile by-product hydrogen chloride was introduced into the absorber tower via the upper end of the condenser. After some process of the crude ester such as distillation, the product can be obtained.
Combining organic compound; microcosmic salt;phosphorous compound
In organic synthesis; polymerization initiator.
1. In pesticide industry, Triphenylphosphine is used in the synthesis of an organophosphorus intermediate, trimethyl phosphite in ester exchange method. And then a series of organophosphorus pesticides such as dichlorvos, monocrotophos and phosphamidon can be further obtained. In addition, it can be used as stabilizers in the synthesis of rubber and resins, antioxidants in polyvinyl chloride, and raw material in the synthesis of alkyd resins and polyester resins.
2. Used in organic synthesis, polymerization initiator, raw materials of antibiotic drugs clindamycin, standard samples in organic trace analysis determination of phosphorus.
3. Widely used in pharmaceutical, petrochemical, paint, rubber and other industries, as catalyst, accelerator, flame retardant, heat and light stabilizer, lubricant, antioxidant etc.
4. In organic synthesis, such as synthesis of phosphorus salts and other phosphorus compounds.
Triphenylphosphine (TPP) is used in the synthesis of organic compounds due to its nucleophilicity and its reducing character. TPP is a highly efficient product that serves successfully in many applications, for example:
- The important ligands of homogeneous catalysts used in petrochemicals and fine chemicals production, as a co-catalyst in isobutanol and n-butanol production.
- The basic raw material of rhodium phosphine complex catalyst, It is used to prepare Wilkinson's catalyst, RhCl(PPh3)3 useful to catalyze the hydrogenation of alkenes and tetrakis(triphenylphosphine)palladium(0) that is widely used to catalyze C-C coupling reactions in organic synthesis.
- in vitamin synthesis and production of pharmaceutical active ingredients, crop protection products and coatings, TPP is used in synthesis of vitamin D2, vitamin A, clindamycin and other drugs. Besides it plays an important role in reactions of plant pigments.
- as an oxidation and UV stabilizer in plastics. In the dye industry, Triphenylphosphine is used as sensitizer, heat stabilizers, light stabilizers, antioxidants, flame retardants, antistatic agents, rubber antiozonants and analytical reagent.
- as an initiator of several polymerization reactions, The anionic phosphine is usually isolated as the trisodium salt which reacts with rhodium to form a complex that finds use in industrial hydroformylation reactions.
- It is involved in the synthesis of biaryl compounds, phosphonium salts and other phosphorus compounds.
- As a reducing agent, it is used to prepare aromatic amines from the corresponding aromatic N-oxides.
ACUTE/CHRONIC HAZARDS: Toxic; when heated to decomposition, emits highly toxic fumes of phosphine and POx.
White, crystalline solid. Insoluble inwater; slightly soluble in alcohol;
soluble in benzene, acetone, carbon tetrachloride.
It is used in the synthesis of organic and organometallic compounds.
It crystallises from hexane, MeOH, diethyl ether, CH2Cl2/hexane or 95% EtOH. Dry it at 65o/<1mm over CaSO4 or P2O5. Chromatograph it through alumina using (4:1) *benzene/CHCl3 as eluent. [Blau & Espenson et al. J Am Chem Soc 108 1962 1986, Buchanan et al. J Am Chem Soc 108 1537 1986, Randolph & Wrighton J Am Chem Soc 108 3366 1986, Asali et al. J Am Chem Soc 109 5386 1987.] It has also been crystallised twice from pet ether and 5 times from Et2O/EtOH to give m 80.5o. Alternatively, dissolve it in conc HCl, and upon dilution with H2O it separates because it is weakly basic, it is then crystallised from EtOH/Et2O. It recrystallises unchanged from AcOH. [Forward et al. J Chem Soc Suppl. p121 1949, Muller et al. J Am Chem Soc 78 3557 1956.] 3Ph3P.4HCl crystallises out when HCl gas is bubbled through an Et2O solution, it has m 70-73o, but recrystallises very slowly and is deliquescent. The hydriodide, made by adding Ph3P to hydriodic acid, is not hygroscopic and decomposes at ~100o. The chlorate (1:1) salt has m 165-167o, but decomposes slowly at 100o. All salts hydrolyse in H2O to give Ph3P [IR, UV: Sheldon & Tyree J Am Chem Soc 80 2117 1958, pK: Henderson & Streuli J Am Chem Soc 82 5791 1960, Kosolapoff, Organophosphorus Compounds, Wiley 1950]. [Beilstein 16 IV 951.] § Available commercially on a polystyrene or polyethyleneglycol support.
The optimum reaction conditions: catalyst dosage 48g, reaction time 8h, the reaction temperature 400 ℃, the yield 63.5%. After sulfur, phosphorus trichloride and benzene reflux reacted directly, the generated triphenyl phosphine sulfide compound were deoxidized into triphenylphosphine by iron powder.
Hazards & Safety Information
Category: toxic substances
Toxicity degree: grading poisoning
Acute toxicity: oral-rat LD50: 700 mg/kg; Oral-Mouse LD50: 1000 mg/kg
Skin irritation Data: rabbit 500 mg/24 hours severe; Eyes-rabbit 500 mg/24 hr mild
Flammability hazard characteristics: thermal decomposition into toxic phosphide
Storage characteristics: ventilated, low-temperature and dry storehouse; stored and transported separately with food raw materials
Extinguishing agent: carbon dioxide, sand, water, foam
- Mitsunobu reactions
The triphenylphosphine combines with DEAD to generate a phosphonium intermediate that binds to the alcohol oxygen, activating it as a leaving group. Substitution by the carboxylate, mercaptyl, or other nucleophile completes the process.
- Ozonolysis reactions
Ozonolysis allows the cleavage of alkene double bonds by reaction with ozone. Depending on the work up, different products may be isolated: reductive work-up gives either alcohols or carbonyl compounds, while oxidative work-up leads to carboxylic acids or ketones.
- Staudinger reactions
Triphenylphosphine reacts with the azide to generate a phosphazide, which loses N2 to form an iminophosphorane. Aqueous work up leads to the amine and the very stable phosphine oxide.
- Appel reactions
The reaction of triphenylphosphine and tetrahalomethanes (CCl4, CBr4) with alcohols is a ready method to convert an alcohol to the corresponding alkyl halide under mild conditions. The yields are normally high.
This reaction is somewhat similar to the Mitsunobu Reaction, where the combination of a phosphine, a diazo compound as a coupling reagent, and a nucleophile are used to invert the stereochemistry of an alcohol or displace it.