Tetraethyl pyrophosphate

Tetraethyl pyrophosphate, abbreviated TEPP, is an organophosphate compound with the formula 2O. It is the tetraethyl derivative of pyrophosphate (P2O74-). It is a colorless oil that solidifies near room temperature. It is used as an insecticide. The compound hydrolyzes rapidly. Tetraethyl pyrophosphate, abbreviated TEPP, is an organophosphate compound with the formula 2O. It is the tetraethyl derivative of pyrophosphate (P2O74-). It is a colorless oil that solidifies near room temperature. It is used as an insecticide. The compound hydrolyzes rapidly. TEPP is a very good insecticide to aphids, mites, spiders, mealybugs, leafhoppers, lygus bugs, thrips, leafminers, and many other pests. TEPP and other organophosphates are the most widely used pesticides in the U.S. due to their effectiveness and relative small impact on the environment. Organophosphates are hydrolyzed and broken down so easily, that the residual period is approximately 48 hours for TEPP. That is enough time for TEPP to do its work, since TEPP is mostly acute toxic with nerve gas-like properties. TEPP has been used for treatment for myasthenia gravis, an autoimmune disease. The treatment would deliver an increase in strength. The synthesis by De Clermont and Moschnin was based on the earlier work by Alexander Williamson (who is well known for the Williamson-synthesis of ethers). Their synthesis made use of ethyl iodide and silver salts to form esters in combination with pyrophosphate. Commercial routes to TEPP often use methods developed by Schrader, Woodstock, and Toy. Triethyl phosphate reacts with phosphorus oxychloride (Schrader-method) or phosphorus pentoxide (Woodstock-method). Alternatively, controlled hydrolysis of diethyl phosphorochloridate delivers the compound: The related tetrabenzylpyrophosphate is prepared by dehydration of dibenzylphosphoric acid: Hydrolysis follows first order kinetic, with t1/2 = 7.5 hours at 25 °C and 3.1 hours at 40 °C. TEPP and most of the other organophosphates are detoxified by hydrolysis. Due to this oxidation and hydrolysis the compound gets more polar, which makes it much easier to excrete via the urine. Note that TEPP is a lipophilic compound, so it can diffuse through tissues easily. This makes it hard to excrete TEPP. Many enzymes hydrolyze TEPP, especially the phosphotriesterases (PTEs). In the serum and the liver, there is a significant higher PTE activity found than in other tissues of mammals.