Dialkyl fluorophosphates

The parent dialkyl ethynylphosphonate was first prepared in 1960 by the addition of stoichiometric ethynylmagnesium bromide to the appropriate dialkyl chlorophosphates in THF. ° The product was isolated in low yield (12-25%), presumably because of side reactions involving the relatively acidic alkynyl proton. The yields can be increased slightly (25-35%) by the use of (toxic) dialkyl fluorophosphates. Despite advances in developing methodologies for the elaboration of dialkyl... 

Dialkyl fluorophosphates. Oxidative fluorination of dialkyl phosphinites occurs on heating with KF and ClsCCN. ... 

In 1944, Hardy and Kosolapoff from the Monsanto Chemical Company patented the production of dialkyl-fluorophosphates as DFP by a procedure based on the reaction of alcohol with PCI3 given dialkylphosphite, then chlorinating and finally fluorinating with NaF (Hardy and Kosolapoff, 1944). 

In 1948, a preparation of DFP was described by Saxmders and Stacey of Cambridge, United Kingdom (Saunders and Stacey, 1948), and a US patent was filed (McCombie et al., 1949). In 1949, another patent was filed for production of mono and dialkyl fluorophosphates. These were produced by treating alkyl polyphosphates with HF and were called dialkoxy phosphoryl monofluoride (Lange, 1949). The monoesters were purported to have low toxicity in mammals but showed fungicidal properties. For that time period in the open literature, preparation of DFP by other complicated methods has been reported, as well as studies of its effects on the nervous systems and as a potential treatment of human diseases. Further efforts regarding the application of fluorophosphoric acid and its salts were focused on the prevention of dental disease (i.e., as an additive in toothpaste). 

Fluorophosphates. As with many other oxo anions, fluorine can replace OH in phosphate to give mono- and di-fluorophosphate salts and esters. The dialkyl monofluorophosphate esters have been found to inhibit cholinesterase in the body and to be exceedingly toxic. The hexafluorophosphate ion, PFg, has been discussed (page 376). 

The reaction with carbonyl fluoride (equation 24) is similar, although yields are not as high". Lopusinski" has advocated the use of bis(trifluoromethyl) disulphide and phos-phorus(III) esters (equation 25) as a convenient reagent for synthesizing S-trifluoromethyl esters. The ester can be isolated or converted directly into the phosphorofluoridate by treatment with fluoride ion. Finally, Russian workers have reported the use of 2-hydrop-erfluoropropyl azide as a reagent that converts dialkyl" or trialkyl phosphites into the corresponding fluorophosphate (equations 26 and 27, respectively). The azide is reported to be inexpensive, readily available and stable ... 

Phosphorodithioic acid, mixed 0,0-bis (isobutyl and pentyl) esters, zinc salt. See Zinc dialkyl dithiophosphate Phosphorofluoridic acid, calcium salt. See Calcium monofluorophosphate Phosphorofluoridic acid, disodium salt. See Sodium fluorophosphate (Na2P03p) Phosphorofluoridic acid, monoammonium salt. See Ammonium monofluorophosphate Phosphorofluoridic acid, potassium salt. See Potassium monofluorophosphate Phosphorothioic acid. See Diazinon Phosphorothioic acid, S-((6-chloro-2-oxooxazxolo(4,5-b) pyridin-3(2H)-yl)methyl) 0,0-dimethyl ester. See Azamethiphos, Phosphorothioic acid, 0-(2,5-dichloro-4-iodophenyl) 0,0-dimethyl ester. See lodofenphos... 

The nature of the active center of chymotrypsin and other hydrolytic enzymes (in general, esterases) has been explored with a specific type of inhibitor, dialkyl phosphate anhydrides, such as diisopropyl-fluorophosphate (DFP). These compounds react with chymotrypsin to add one, and only one, phosphorus per molecule and form a completely inactive compound. The inactivated molecule yields phosphoserine on... 

As we have mentioned above, strongly adsorbed species are needed for good stabilization of nanoparticles. Many ions generally employed in ionic liquids, like the cations tetraalkylammonium (Nk,i,nvn ), tetraalkylphosphonium (Pk.iAnV), and 1,1-dialkyl-pyrrolidinium (CmCnPyr ) and the anions bis(trifluoromethanesulfonyl)amide (Tf2N-), trifluoromethanesulfonate (CF3SO3 ), alkylsulfate (CnOSOs ), tetrafluoroborate (Bp4-), hexa-fluorophosphate (PFe") sue weakly coordinating and, thus, need to be complemented with an appropriate counter ion to stabilize nanopartides efficiently. 

After dissolving in an organic solvent, LiPFg will decompose to LiF and PF5 at 60°C. The produced PF5 can then react with the dialkyl carbonate to form differenf decomposifion producfs such as carbon dioxide, ether, fluorine-substituted hydrocarbons, POF3, PO2F, and fluorophosphates, as shown in the following [5] ... 

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