Bis- methylphosphonic acid

CgH gO ()N2P2, ethylenedinitrilo-JV,iV-bis(methylphosphonic acid)-/V, A,-diacetic acid, HgL ... 

The partially protonated cyclen and cyclam and their derivatives are present in aqueous solution in some stable conformations stabilized by intramolecular hydrogen bonds. It leads, for example, to broad signals in NMR at room temperature and intermediate pH. Such hydrogen bond-stabilized structures are sometimes rather stable as it was proved, for example, in the case of l,8-bis(methylphosphonic acid) cyclam derivatives where solution structure is probably the same as found in the solid state <2000CCC1289>. These closed structures are opened after full protonation. 

Nucleophilic Reactions.—Attack on Saturated Carbon. Selected examples of the Arbusov reaction include phosphorylation of the chloroacetophenones (1) to give phosphonates, which cyclized to (2) in the presence of acid chlorides,1 formation of the azodiphosphonate (3) from 2,2 -dichloro-2,2 -azopropane,2 3 and the reaction of 2-chloro-3,4-dihydro-3-oxo-2//-l,4-benzothiazine (4) with triethyl phosphite to give the 2-phosphonate (5), which is used as an olefin synthon.8 Bis(trimethylsilyl) trimethylsiloxymethylphosphonite (6) has been synthesized by silylation of hydroxy-methylphosphonous acid, and, as expected, undergoes a normal Arbusov reaction with alkyl halides to give the phosphonates (7).4 This series of reactions, followed by... 

ToF-SIMS, and AFM results, the formation of ordered monolayers of octade-cylphosphoric acid on a Ta205 surface involves both monodentate and bi-dentate phosphate species [135]. In the case of goethite, (y-AlOOH), it was found that methylphosphonic acid bound to the surface as a monodentate or a bidentate species depending on the pH and the concentration [163]. 

Methylenation. This phosphonate ester is generally regarded as unsuitable for methylenation of ketones, even though the anion forms the intermediate adduct in satisfactory yield. However, under suitable experimental conditions, this reagent was used for methylenation of 1 to give 2 in 90% yield, higher than that obtained with methylphosphonic acid bis(dimethylamide) (78%).1 The optimum yield is obtained if exactly 2 equiv. of base and 1 equiv. of water are used to quench the adduct before cycloelimination. 

Figure 2. The effect of derivatization on methylphosphonic acid (a) methyl phosphonic acid analyzed as solid KBr pellet, (b) dimethyl methylphosphonate analyzed with cryodeposition-FTIR, and (c) bis(trimethylsilyl) methylphospho-nate (CAS 18279-83-9) analyzed with cryodeposition-FTIR (Source M. Soderstrom, unpublished results)...

Diisopropylaminoethyl) O -ethyl methylphosphonate 2-(bis( 1 -Methylethyl)amino)ethyl methylphosphonic acid C H26N03P 71840-26-1 Present in tonne containers... 

Conventional intermediates based on m3>o-inositol have been adapted for the synthesis of methylphosphonate analogues of inositol phosphoric acids. Thus, 1.2,3,4,6-pentabenzoyl-myo-inositol was the. source (using reactions indicated in Scheme 25) of the 5-methylphosphonate (241) 3,6-di-O-benzyl-l, 2-O-isopropylidene-myo-inositol furnished the 4,5-bis(methylphosphonate) (242), and compound (44) yielded the... 

Methylphosphonic acid, bis [(5-ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphorinan-5-yl) methyl] ester... 

Phosphonic acid, methyl-, bis [(5-ethyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl) methyl ester, p,p -dioxide Phosphonic acid, methyl-, bis [(5-ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphorinan-5-yl) methyl ester Phosphonic acid, methyl-, bis [(5-ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphorinan-5-yl) methyl ester, p,p -dioxide. See Methylphosphonic acid, bis [(5-ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphorinan-5-yl) methyl] ester... 

Methylene bis phosphinates (6.745e), with a central carbon chain, can be obtained from methyl phosphinic esters (6.253), or from methylphosphonous diesters, which, like phosphites, undergo Arbusov rearrangements with condensation (6.749). Methylene bis phosphinic acid can be obtained by reaction (6.750). This compound is reasonably stable in hot water, but on boiling it eventually gives methylene bis phosphonic acid, (H0)20P-CH2-P0(0H)2 [7]. 

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