Alkylphosphonates Methylphosphonates

Purdon JG, Pagotto JG, Miller RK. 1989. Preparation, stability, and quantitative analysis by gas chromatography and gas chromatography-electron impact mass spectrometry of tert-butyldimethylsilyl derivatives of some alkylphosphonic and alkyl methylphosphonic acids. J Chromatogr 475 261-272. 

Reactions and Properties of Phosphonic and Phosphinic Acids and their Derivatives.-A free radical mechanism has been proposed to account for the cleavage of the phosphorus-carbon bond in the alkylphosphonic acids (155) by E coli to give a mixture of alkane (methane only, from methylphosphonic acid) and terminal alkene. 

Related to the Schedule 1 family of alkyl/cyclo-alkyl alkylphosphonofluoridates, are three important classes of compounds. These are the dialkyl/dicyclo-alkyl alkylphosphonates, the alkyl/cycloalkyl alkylphosphonates and the methyl alkyl/cycloalkyl alkylphosphonates, all belonging to the Schedule 2.B.4 chemicals. Per definition, Schedule 2.B.4 represents the largest number of chemicals of CWC interest. The first class consists of known impurities of nerve agents, the second class consists of the primarily formed hydrolysis products of nerve agents, and the third class, the corresponding methyl esters-DMMP (dimethyl methylphosphonate) and DIMP (diisopropyl methylphosphonate) (see Table 1) are... 

Figure 8. LC/MS mass chromatograms, positive APCI showing the detection of four isomeric alkyl alkylphosphonic acids (1 Hg/ml) and two dialkylalkyl phosphonates (10 p,g/ml) (upper), negative APCI showing selective detection of the phosphonic acids, a. i-PrMPA and EEPA (unresolved), b. methyl n-PrPA, c. n-PrMPA, d. ethyl methyl methylphosphonate, and e. dimethyl ethylphosphonate (lower)...

Dialkyl alkylphosphonates are of interest as analytes for a number of reasons. They may be present as impurities in nerve agents, and as such may be useful indicators of use or production as they are much more stable in the environment an example is diisopropyl methylphosphonate found in sarin. Dialkyl methylphosphonates may be formed in decontamination reactions of nerve agents in basic formulations containing alcohols or cellusolves. They are also important precursors to nerve agents, for example, dialkyl methylphosphonates are converted to the key... 

A. E. Arbuzov and Diinin were the first to show that the reaction of alkyl halides (Mel, BnCl) with the sodium or potassium salts of diethyl l-(ethoxycaibonyl)methylphosphonate results in the formation of diethyl l-(ethoxycarbonyl)alkylphosphonates. By this procedure, the combinations of... 

Figure 1 shows the structures of the Schedule 1 alkylphosphonofluoridates and the Schedule 2 alkyl methylphosphonic acids and the hydrolysis reaction. The most common alkylphosphonic acids and the hydrolysis reaction. The most common alkyl groups and the ones examined in this study (ethyl, isopropyl, isobutyl, cyclohexyl) and pinacolyl) are shown at the bottom of Figure 1. 

Alkylphosphonates are a neutral modification in which a non-bridging oxygen is substituted for an alkyl group, the most widely studied in the past being methylphos-phonates. However, methylphosphonate derivatives are infrequently used because they have solubility problems, but have been used in mechanistic studies of the junctionresolving enzyme T7 endonuclease A number of other nucleoside phosphonate derivatives have been described. An improved microwave-assisted Michaelis-Arbuzov method for synthesis of substituted-phosphonates is reported, " and the reaction of dialkyl phosphate derivatives with the 5 -aldehyde-derivative of nucleosides leads to high yields of 5 -C-phosphonates. The reactivity of 5 -C-phosphonates towards periodate oxidation has been reported. Various nucleoside phosphonates have been... 

The further synthetic strategy was thus focused on the modifications of (9,(9-dimethyl [-(substituted phenoxyacetoxy)alkylphosphonates scaffold. As many heterocyclic compounds had shown remarkable biological properties, we were interested in the design of heterocycle-containing 1-(substituted phenoxyacetoxy) alkylphosphonates. Different heterocyclic group such as fiiryl, thienyl, or pyridyl group as R was introduced to IC to form (9,(9-dimethyl [-(substituted phenoxyacetoxy)-l-(fur-2-yl)methylphosphonates IG, (9,(9-dimethyl [-(substituted phenoxyacetoxy)-l-(thien-2-yl)methylphosphonates IH and (9,(9-dimethyl [-(substituted phenoxyacetoxy)-l-(pyrid-2-yl)methylphosphonates U (Scheme 2.18). 

The structure of alkali metal salts of 0-alkyl 1-(substituted phenoxyacetoxy) alkylphosphonic acids IIA-IIE was confirmed by elemental analysis and characterized by IR, H NMR. Some of them were further characterized by NMR and mass spectrometry. The structure of sodium O-methyl l-(2,4-dichlorophenoxy-acetoxy)-l-(furan-2-yl)methylphosphonate IIB-20 was further analyzed by X-ray single-crystal diffraction. 

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