- METHOD OF THE SYNTHESIS OF DIALKYL HALOALKYLPHOSPHONATES AND DIALKYL HALOALKYLOXYALKYLPHOSPHONATES
-
The invention deals with the method of the synthesis of dialkyl haloalkylphosphonates and dialkyl haloalkyloxyalkylphosphonates via a microwave-heated Michaelis-Arbuzov reaction of trialkylphosphites with dihaloalkanes or bis(haloalkyl)ethers in a closed vessel, during which the reaction mixture, containing a dihaloalkane or bis(haloalkyl)ether and a trialkylphosphite, is heated with microwave radiation with the standard frequency (2.45 GHz) to reach a reaction temperature which is specific for each individual halogen. In the subsequent reaction of the first dihaloalkane or bis(haloalkyl)ether halogen atom with trialkyl phosphite, the desired dialkyl haloalkylphosphonate or dialkyl haloalkyloxyalkylphosphonate is formed, but the reaction of its halogen atom with the so-far present trialkylphosphite, leading to the creation of the relevant bisphosphonate, no longer takes place. In the case of an inhomogeneous reaction mixture, also the desired product in the amount of 0.1-5 molar % is added to the reaction mixture for its homogenization, which homogenizes it and thus precludes its uncontrollable overheating. The entire process of synthesis is more effective, faster, less expensive and more environmentally friendly than the methods described so far in the literature. The possibility of performing the described procedure also in a continuous-flow microwave reactor allows industrial production with minimal demands on an optimization of the reaction conditions for larger quantities, eliminates some security risks, dramatically reduces the spatial demands in production and reduces the need for the usage of large-tonnage industrial reactors.
- -
-
Page/Page column 19-20
(2012/02/13)
-
- Efficient and 'green' microwave-assisted synthesis of haloalkylphosphonates via the Michaelis-Arbuzov reaction
-
This paper deals with a novel, efficient and environmentally friendly synthesis of dialkyl haloalkylphosphonates via a microwave-assisted Michaelis-Arbuzov reaction. The approach is solventless, requires only one equivalent of each of the starting compounds, and provides high yields of pure products from which the impurities are easy to remove. The process has been optimised for batch and flow reactors and is especially profitable for the production of key intermediates in synthesis of Ethephon or acyclic nucleoside phosphonates such as adefovir, tenofovir, and cidofovir. The Royal Society of Chemistry.
- Jansa, Petr,Holy, Antonin,Dracinsky, Martin,Baszczynski, Ondrej,Cesnek, Michal,Janeba, Zlatko
-
supporting information; experimental part
p. 882 - 888
(2011/06/20)
-
- Synthesis of methylene bisphosphonates from carbon disulfide and phosphites via desulfurization: A mechanistic study
-
The reaction of carbon disulfide with an excess of sodium dialkylphosphite in an aprotic solvent led to the formation of the carbanion of methylene bisphosphonate and sodium thiophosphate. The mechanistic study of this unexpected reaction, using both 31P
- Heuze,Lemarie,Vazeux,Gulea,Masson,Sene,Jaffres,Alberti,MacCiantelli
-
experimental part
p. 820 - 829
(2009/12/03)
-
- Preparation of halohydrocarbyl phosphonic acid diesters
-
In a process for the production of halohydrocarbyl phosphonic acid diesters via a Michaelis-Arbuzov type reaction which results in high conversion and selectivity of product with ease of purification; the improvement comprises reacting hydrocarbyl halide with trihdydrocarbyl phosphite in a molar ratio of about 6:1 and in the presence of an effective amount of a polarity lowering additive.
- -
-
Page/Page column 5-6
(2008/06/13)
-
- Preparation of fluorinated compounds
-
A method for the preparation of a fluorinated Phosphonate having the formula (RO)2PO CFR′R″ comprises treating a phosphonate of the formula (RO)2PO CHR′R″, or a metal salt thereof, with fluorine. R is an alkyl group R′ is hydrogen or alkyl and R″ is hydrogen, alkyl or another group.
- -
-
-
- ZUR SYNTHESE UND REAKTIVITAET METHYLENVERBRUECKTER DIPHOSPHORYLVERBINDUNGEN
-
An improved high-yield Arbusov-type synthesis for diphosphorylmethanes with different substituents on both phosphorus atoms (4, 5, 7) by the reaction of isopropyl diphenylphosphinite or diisopropyl phenylphosphonite with diisopropyl bromomethylphosphonate (1) or isopropyl phenyl-bromomethylphosphinate (2), respectively, is described. 1 and 2 are available in yields of about 50 percent by the reaction of an excess of methylene bromide with triisopropylphosphite or diisopropyl phenylphosphonite, respectively.The metalation of the symmetrical and unsymmetrical diphosphorylmethanes 3-8 with NaH in toluene yields the corresponding carbanionic salts 3A-8A.Their structure and reactivity are investigated by means of 31P NMR spectroscopy and Horner-reactions with benzaldehyde.Regioselective monomethylation at the central carbon atom of 3-7 is performed using the phase-transfer technique.With exception of the phosphono-phosphinate derivative 14, on this way the appropriate 1,1-diphosphorylethanes 13 and 15-17 are obtained in high yield.Key words: diisopropyl bromomethylphosphonate; isopropyl phenyl-bromomethylphosphinate; diphosphorylmethanes; 31P-NMR; HORNER-reactions; 1,1-diphosphorylethanes
- Goebel, R.,Richter, F.,Weichmann, H.
-
-
- THE DEHALOGENATION OF DIHALOGENOMETHYLENEBISPHOSPHONATES
-
Tetraesters of dihalogenomethylenebisphosphonic acids undergo nucleophilic dehalogenation with potassium fluoride or hydroxide in solution in acetonitrile in the presence of -crown ether.Fluoride ion is the best nucleophile for dehalogenation and there is no evidence for nucleophilic displacement of halide ion by attack at the central atom of the methylenebisphosphonic esters.Conditions have been developed for the monodehalogenation of tetraisopropyl dibromo- and dichloromethylenebisphosphonates in good yield.
- Hutchinson, D. W.,Semple, G.
-
-
- Cosmetic deodorant preparations containing alkane diphosphonic acid esters
-
Alkane diphosphonic acid esters having the formula STR1 wherein R is a straight- or branched-chain alkyl radical having 1 to 6 carbon atoms; and n is an integer of 1 to 6 are deodorants in anhydrous cosmetic preparations for the suppression of body odor.
- -
-
-