General Description
A clear colorless liquid with a strong foul odor. Flash point 130°F. Less dense than water and insoluble in water. Vapors heavier than air.
Reactivity Profile
TRIETHYL PHOSPHITE(122-52-1) is colorless, moderately toxic liquid, combustible. Flammable when exposed to heat or flame. When heated to decomposition TRIETHYL PHOSPHITE(122-52-1) emits toxic fumes of oxides of phosphorus [Lewis, 3rd ed., 1993, p. 1271].
Air & Water Reactions
Flammable. Insoluble in water.
Health Hazard
Exposure to high concentrations may cause headache, nausea, and dizziness due to reduced chlolinesterase activity.
Fire Hazard
Special Hazards of Combustion Products: May form hazardous decomposition products.
Chemical Properties
Triethyl phosphite is a clear colorless liquid with a strong foul odor. Insoluble in water; soluble in alcohol and ether. Combustible.Vapors heavier than air.
Preparation
Triethyl phosphite is produced in a closed system by reaction of phosphorous trichlorid and ethanol in the presence of an inorganic or organic base. The product is purified by distillation (Bayer AG, 2002a).
Triethyl phosphite is exclusively used as an intermediate for the manufacturing of different products: flame retardants (about 60 %), optical brighteners (about 15 %), pesticides (about 15 %), antioxidants (about 5 %), and pharmaceuticals (about 5 %).
Reactions
This reaction is currently used for the preparation of synthetically useful phosphonate reagents employed in modified retinal studies. Thus, diethyl 3-alkoxycarbonyl-2-propenylphosphonates are prepared in 72-91% yields by the reaction of methyl or ethyl 4-bromocrotonates with triethyl phosphite at 150-160°C. Similarly, diethyl 3-(ethoxycarbonyl)-2 methyl-2-propenylphosphonate is prepared in 81% yield from triethyl phosphite and ethyl 3-methyl-4-chlorocrotonate by heating at 180- 200°C.The diethyl (E)- and (Z)-3-ethoxycarbonyl-3 fluoro-2 -methyl-2-propenylphosphonates are respectively obtained from triethyl phosphite and (E)- or (Z)-4-bromo-2-fuoro-3-methyl-2-butenoates at 140°C.
Flammability and Explosibility
Flammable
Toxicity evaluation
The acute toxicity after oral, dermal, and inhalation exposure is relatively low. The oral LD50s in rats ranged between 1840 mg/kg bw (females) and 2470 mg/kg bw (males). Symptoms of rapid breathing and tremors were observed prior to death. In mice LD50 values above 3700 mg/kg bw were recorded. The 6-hour inhalation LC50 with an aerosol of 1.6-3.5 μm MMAD in rats was between 11,100 mg/m3 (females) and 11,600 mg/m3 (males). Clinical signs included eye and upper respiratory irritation, salivation and rapid, shallow breathing. The dermal LD50 in rabbits was between 2800 mg/kg bw (males) and > 3000 mg/kg bw (females).
