Hexaethyl tetraphosphate

Of the three organic phosphorus insecticides—hexaethyl tetraphosphate, tetraethyl pyrophosphate, and parathion—the first two have been shown to be mixtures (36) that contain tetraethyl pyrophosphate as the principal active ingredient. Several methods have been proposed for the determination of this compound in the commercial products (25, 35). All are based on the separation of the tetraethyl pyrophosphate from the related ethyl phosphates, followed by its hydrolysis to diethyl orthophosphoric acid and titration with standard alkali. Both hexaethyl tetraphosphate and tetraethyl pyrophosphate are soluble in water and are rapidly hydrolyzed to monoethyl and diethyl orthophosphoric acid. This rapid hydrolysis to nontoxic products greatly limits the duration of the in- secticidal effectiveness of tetraethyl pyrophosphate, but it also eliminates the danger of toxic residues on the crops treated. 

The first of Schrader s organic phosphorus anticholinesterases to find rather large-scale application as an insecticide in Germany during World War II was his so-called hexaethyl tetraphosphate (37), which the Germans called Bladan. Schrader obtained German and United States patents (39) on this material, and ascribed to it a branched-chain structure. Hall and Jacobson (24) found that it is a mixture of ethyl polyphos-... 

In all cases the reaction products are mixtures of ethyl polyphosphates, and, on the basis of elementary analysis, they approximate the empirical formulas given in the above equations. In Equations 3 and 5 the product has been arbitrarily called hexaethyl tetraphosphate, which may contain 8 to 20% of the active tetraethyl pyrophosphate. In Equations 4 and 6 the products have been called technical tetraethyl pyrophosphate, which may contain up to 40% of pure tetraethyl pyrophosphate. Hexaethyl tetra-phosphate has also been made from phosphoric anhydride and diethyl ether by a process recently patented by Adler (1). 

Diisopropyl fluorophosphate (DFP DYFLOS) Hexaethyl tetraphosphate (HETP) 0.025% topical (eye)... 

The relationship between particle size and foliage injury was shown in work with liquefied gas aerosol formulations of hexaethyl tetraphosphate for greenhouse applications (I). Particles larger than 20 microns diameter injured some varieties of foliage. Increasing pressure and using smaller nozzles lowered the mass median diameter but did not eliminate the maximum sized particles. The problem was finally solved with a low-concentration formulation, in which the particles larger than 20 microns in diameter could be eliminated. 

Hexaethyl tetraphosphate M ethylbenzyl alcohol m-Benzeneaisulfonic acid... 

Ethylbenzyl chloride Ethylene dibromide V,V -Dinitroethylenediamine Hexaethyl tetraphosphate M ethylbenzyl alcohol m-Benzenedisulfonic acid Methylbenzyl chloride V-Bromosuccinimide Octamethyl pyrophosphoramide p-Aminosalicylic acid Pentaerythritol tetranitrate Tris-(/3-chloroethyl) amine Tetraethylammonium bromide Tetraethyl pyrophosphate 2,2,6,6-Tetramethylolcyclohexanol... 

Gallic Acid 149-91-7 Hexaethyl Tetraphosphate 757-58-4 Iron (II) Chloride 7758-94-3... 

Note Hexaethyl tetraphosphate and compressed gas mixture not accepted by air or by passenger rail. For details consult regulations. 

Even though Schraeder reported that he obtained hexaethyl tetraphosphate, subsequent studies showed that actually various reorganization reactions occurred. The reaction mixture contained about 20 - 25% tetraethyl pyrophosphate. Tetraethyl pyrophosphate was the active insecticide ingredient. One of my laboratory colleagues discovered another... 

When phosphoryl chloride and triethyl phosphate are used in a ratio of 1 3 in Schrader s process, or phosphorus pentoxide and triethyl phosphate in a ratio 1 2 in Woodstock s process, the product formed consists mainly of hexaethyl tetraphosphate (HETP, 9) (Schrader, 1939 Woodstock, 1942)... 

Schrader, by the action of 3 mol. of triethyl phosphate on 1 mol. of phosphorus oxychloride, obtmned what he considered to be hexaethyl tetraphosphate (H.E.T.P.) ... 

Hexaethyl Tetraphosphate 1611 55 Hydrazine Solution, with not more 2030 59... 

Hexaethyl Tetraphosphate Mixture 2783 55 Hydriodic Acid, and Solutions 1787 60... 

Hexaethyl tetraphosphate Ethyl tetraphosphate Cl2H3o 13p4 767-68-4 606.263 iiyg -40 dec 160 1.2917" 1.4273" vs ace, bz, EtOH... 

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