Pinacolyl methyl phosphonate

Pinacolyl methyl phosphonate MAA/DVB 4MU Toluene 5-30 nmol 5 nmol [82]... 

FIGURE 52.1. Metabolic detoxification of warfare nerve agents tabun, sarin, soman, and VX in mammals in vivo. Chemical names of metabolites are EDMPA - ethyl dimethylaminophosphoric acid, IMPA - isopropyl methylphosphonic acid, PMPA - pinacolyl methyl-phosphonic acid, EMPA - ethyl methylphosphonic acid, and MPA - methylphosphonic acid. 

Chemistry The synthesis of soman is similar to that of sarin. The major alteration is that pinacolyl alcohol replaces isopropanol. Soman hydrolyzes over a range of pHs, with pinacolyl methylpho-sphonate and fluoride ions being the initial products. Subsequent hydrolysis of pinacolyl methyl-phosphonate is similar to the aging process associated with GD poisoning (below) (Michel et al., 1967). 

Photocatalytic activity has also been observed with some of these compounds. For instance, titanium dioxide nanoparticles were able to degrade 2-chloroethyl sulfide (mustard) in liquid and gas phase, a series of warfare agents like diethyl sulfide, dimethyl methyl phosphonate, diethyl phosphoramidate, pinacolyl methyl-phosphonate, and butylaminoethanthiol, and pesticides such as lindane, methyl parathion, and dichlorvos upon exposure to ultraviolet light (Vigo and Thibodeaux, 2001 Sundarrajan et al., 2010). Zinc oxide nanoparticles were incorporated into polymers used to produce electrospun coating on cotton fabrics and provided them with photocatalytic-activated antimicrobial properties (Munoz-BonUla and Femandez-Garcia, 2012). 

GD (soman pinacolyl Hydrolysis Methyl phosphonic acid (MPA) High RfD 20 -ig/kg/day... 

GD dissolves in water but the rate of hydrolysis under neutral conditions is slow (Yang et al. 1992). Qualitatively, the hydrolysis of GD is similar to that of GA however, the reaction rate is fivefold slower than that of GA, and GD has an estimated half-life of about 60 hr at pH 6 and 25 °C (Hambrook et al. 1971). The reaction is both acid- and base catalyzed, resulting in a hydrolysis curve similar to that of GA (Clark 1989). The primary hydrolysis product of GD is pinacolyl methylphosphonic acid, which slowly hydrolyzes, with the release of pinacolyl alcohol, to methyl phosphonic acid (Fig. 6) (Clark 1989 Kingery and Allen 1995). At pH >10, hydrolysis to pinacolyl methylphosphonic acid occurs within a few minutes (Yang et al. 1992). Because an acid is produced, the pH will decrease, lessening the rate of hydrolysis. GD stored at pH 6 for 8 wk had a pinacolyl methylphosphonic acid/methyl phosphonic acid ratio of 250 (Hambrook et al. 1971), which Kingery and Allen (1995) extrapolated to a half-life of 27 yr. The C-P bond is very resistant to hydrolysis. Hydrolysis products are listed in Table 37. 

Fig. 1 HPLC-ESP MS reconstructed (total) ion chromatogram from a standard mixture of alkyl phosphonic acids at a concentration of 1 p-g/ml each 1) methylphosphonic acid (MPA) 2) ethylphosphonic acid (EPA) 3) methyl ethylphosphonic acid (MEPA) 4) ethyl methylphosphonic acid (EMPA) 5) ra-propylphosphonic acid (nPrPA) 6) ethyl ethylphosphonic acid (EEAP) 7) isopropyl methylphosphonic acid (iPrMPA) 8) n-propyl methylphosphonic acid (nPrMPA) 9) isopropyl ethylphosphonic acid (iPrEPA) 10) n-propyl ethylphosphonic acid (nPrEPA) 11) isohutyl methylphosphonic acid (iBuMPA) 12) cyclohexyl methylphosphonic acid (CHMPA) 13) pinacolyl methylphosphonic acid (PinMPA).

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