Diethyl phosphite

Diethyl phosphite is an organophosphorus compound, a colorless liquid with a tetrahedral structure. Its molecular formula is C4H11O3P, its molecular weight is 138.1 g/mol, its boiling point is 187-188°C, its relative density is 1.072 g/cm3, its refractive index is 1.4080, and its flash point is 90°C. Diethyl phosphite is soluble in organic solvents such as ethanol and ether, but is incompatible with strong oxidants, strong acids, acyl chlorides, and strong bases. It may decompose when exposed to moisture and is flammable. Diethyl phosphite is a commonly used reagent that can use the high reactivity of the PH bond to generate other organophosphorus compounds.

The laboratory preparation method is to add 75mL of carbon tetrachloride and 82.8g (1.8mol) of absolute ethanol to the reaction flask, and dropwise add 70.2g (0.51 mol) dissolved in 50mL of carbon tetrachloride under nitrogen protection and stirring ) Phosphorus trichloride solution is added after about 1.5h, the temperature rises in the whole process. After the addition, the temperature is raised to 70°C for 1h, the solution changes from colorless to light yellow, and then the solvent is distilled off under reduced pressure with a water pump, oil pump The product was distilled off under reduced pressure. 3C2H5OH+PCl3→(C2H5O)2PHO+C2H5Cl+2HCl↑The industrial method is to add anhydrous ethanol and benzene to the enamel stirring kettle, cool and stir, add phosphorus trichloride dropwise at 10～20℃, drop within 1h After the addition is complete, react at this temperature for 1 hour. The reaction material is transferred to an enamel neutralizing kettle, and it is neutralized by ammonia gas at 10-20°C to pH=6-7. Ammonium chloride is filtered off, and the filtrate is distilled off first, then O, O'-diethyl phosphite was distilled off under reduced pressure.

Diethyl phosphite (DEPI) is a versatile reactive intermediate used in the production of various phosphorus based substances. It may be used to prepare the nickel chloride-diethyl phosphite system, efficient catalyst for the cross-coupling reaction between various functionalized arylzinc halides and aryl bromides, triflates and activated chlorides.It may be used: in the stereoselective synthesis of β-fluorinated alkylphosphonates Used in synthesis of homoallylic bromide Used in synthesis of serie