Methylphosphonic acid groups

The superior coordinating capacity of phosphonate over carboxylate is illustrated in the 9Be NMR spectra in Fig. 25 (260). The similarity of the spectra obtained by reaction of BeS04 and methylphosphonic acid or phosphonacetic acid indicates that the carboxylate group is not bound to the beryllium under these experimental conditions. It should be noted that substitution of a water molecule by a phosphonate ligand causes the 9Be resonance to move upfield when it co-ordinates, as does the fluoride ion (271), the only other monodenate ligand... 

The ester group is then hydrolysed, and the hydrolysis normally stops at the MePO(OH)2 stage. More vigorous conditions are required to rupture the Me—P bond. Thus the normal hydrolysis product of D.F.P. and of tabun, namely, phosphoric acid, will give a positive test with ammonium molybdate, whereas the product from sarin, namely, methylphosphonic acid, will not respond to this test. Vigorous reagents such as hot nitric acid and ammonium persulphate will break the C—P link and then a positive test for phosphate is obtained with ammonium molybdate. Sarin can be prepared in a variety of ways. Three... 

Methyl-lH-imidazol-l-yl group, present in a side chain of perhydro-pyrido[2,l-c][l,4]oxazin-6-one skeleton was quaternized by reacting with chloromethyl di-ferf-butyl phosphate in the presence of Nal and Hiining s base in DME at 80 °C for 2 h, followed by treatment TFA in CHCI3 to give methylphosphonic acid derivative (08WOP2008/013213). 

All Schedule 2 chemicals are analyzable by NMR, except arsenic trichloride, which does not possess a useful nucleus. Either an organic solvent or D20 is used. Note that the hydrolysis products of alkylphosphonofluoridates (l.A.l), alkylphos-phonothiolates (1.A.3), alkylphosphonyl difluorides (1.B.9), alkylphosphonites (1.B.10), chlorosarin (l.B.ll), and chlorosoman (1.B.12), which have an alkyl group (Me, Et, n-Pr, or i-Pr) finked direefly to a phosphorus, all belong to Schedule 2, group B.4, and NMR analysis for them is made either in D20 or in an organic solvent. By way of example, NMR spectral parameters of isopropyl methylphosphonate, pinacolyl methylphosphonate, methylphosphonic acid, 0-ethyl methylthiophos-phonate, N,N-dimethylphosphoramidic dichloride,... 

A diamide of methylphosphonic acid [MeP(0)(NBu2)2, a phosphono-amidate] has been shown to lose the methyl group and substitute into indole (80JGU618) there are no other reports of this reaction. 

The arbitrary name VX relates to a group of D,5-diesters of methylphosphonic acid ROPO(CH3)S(CH2)2N(Rl)2. D-Isobutyl 5-2-(diethylamino)ethyl methylphosphonothioate (R= /Bu, R1 = Et), produced since 1972 exclusively in the former Soviet Union, was generally referred to as Russian VX or RVX (CAS 159939-87-4). The synonyms are VR VA phosphonothioic acid methyl-, 5-[2-(diethylamino)ethyl] D-(2-methylpropyl) ester D-isobutyl5-2-(diethylamino)ethyl methylthiophosphonate D-isobutyl 5-(W-diethylaminoethyl) methylphosphonothioate and Russian V-gas. The brutto formula of RVX is C11H26SNPO2 (MW 276.37). The stmctural formula of RVX is presented in Figure 7.1. 

The fluorophosphonates GB and GD hydrolyze first through the loss of fluorine and second, more slowly, through the loss of the alkoxy group (Kingery and Allen 1995 MacNaughton and Brewer 1994). Under acidic conditions, the products of GB hydrolysis are isopropyl methylphosphonic acid and fluoride the former slowly hydrolyzes to methyl phosphonic acid with the loss of isopropanol (Fig. 5). According to Clark (1989), alkaline hydrolysis results in isopro-... 

A series of 0-alkyI methylphosphonic acids were synthesized by reaction of methylphosphonic dichloride with appropriate alcohol. Obtained acids, after derivatization were examined using GC/MSD/FTIR Hewlett Packard system. 0-alkyl methylphosphonic acids are important group of degradation products of some CW agents and the analytical data of those acids may be useful for analytical control of CW destruction process. 

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. 

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