Methylene phosphonate

Diethylenetriaminepenta (methylene phosphonic acid) [DETPMP] is the most effective sequestrant for barium sulfate. DETPMP has a sequestration value of 820 mg CaC03/g product at pH 11. The hexa-sodium salt has MW of 705. Examples include Dequest 2066 and Mayoquest 1860. 

Furthermore, the GPO procedure can also be used for a preparative synthesis of the corresponding phosphorothioate (37), phosphoramidate (38), and methylene phosphonate (39) analogs of (25) (Figure 10.20) from suitable diol precursors [106] to be used as aldolase substrates [102]. In fact, such isosteric replacements of the phosphate ester oxygen were found to be tolerable by a number of class I and class II aldolases, and only some specific enzymes failed to accept the less polar phosphonate (39) [107]. Thus, sugar phosphonates (e.g. (71)/(72)) that mimic metabolic intermediates but are hydrolytically stable to phosphatase degradation can be rapidly synthesized (Figure 10.28). 

Phosphonate analogs to phosphate esters, in which the P—0 bond is formally replaced by a P—C bond, have attracted attention due to their stability toward the hydrolytic action of phosphatases, which renders them potential inhibitors or regulators of metabolic processes. Two alternative pathways, in fact, may achieve introduction of the phosphonate moiety by enzyme catalysis. The first employs the bioisosteric methylene phosphonate analog (39), which yields products related to sugar 1-phosphates such as (71)/(72) (Figure 10.28) [102,107]. This strategy is rather effective because of the inherent stability of (39) as a replacement for (25), but depends on the individual tolerance of the aldolase for structural modification close... 

G. M. Graham, S. J. Dyer, and P. Shone. Potential application of amine methylene phosphonate based inhibitor species in HP/HT (high pres-sure/high temperature) environments for improved carbonate scale... 

Fig. 16a and b. Wedge-test crack length (in.) of aluminum/thermoset (American Cyanamid FM123-2) joints as a function of exposure time to a 100% r. h.,60 °C environment, a) FPL, PAA, FPL + 10 ppm nitrilotris (methylene phosphonic acid (NTMP)831 and b) PAA and PAA + 300 ppm NTMP pretreatments were employed 1391 (Reprinted with permission from Chapman and Hall, LTD.)... 

Acetyl hypofluorite reacts smoothly with 1,3-dicarbonyl compounds or their enolates264. Even lithium enolates of monocarbonyl derivatives265 or methylene phosphonates, analogous to the AZT drug266, can be fluorinated directly, eliminating the need to prepare the... 

Substituted azetidine 2-phosphonic acids 4 were prepared in enantiopure form via N-alkylation of the starting P-amino alcohols with a methylene phosphonate moiety, followed by sequential chlorination and stereoselective 4-exo-tet ring closure <02TL4633>. 

Polystyrene-methylene-phosphonic acid Resorcinol arsonic acid/ formaldehyde copolymer Duolite ES 467... 

Uptake of methylphosphonic, aminomelhyl-phosphoniCs hydroxymethyl-phosphonic. l-hydro ycthane-(l, 1-diphosphonic), iminodi-(methylphosphonic). nitnlotris-(methylene-phosphonic). elhylcncdimtnlotetrakis-(methylcnephosphonic), and diethylenetruu-tnlopentakis-(methylenephosphonic) acids was interpreted in terms of formation of 2-9 different surface species whose stability constants are interrelated, namely, log K = (1145 + 7.31 nH2.53 + 0 46n>Z where n is the surface protonation level and Z IS the surface complex charge, and fully deprotonated anions are componenls. Adsorplion isotherms at constant pH were also obtained in the presence of buffers lEP at pH 7 2 in dispersion titrated with Na COj. pristine lEP at pH 8.5. 

Nitrilotris(methylene phosphonic acid), sodium salt. Amlnoth(methylene phosphonic acid), sodium salt EINECS 243-900-0 Nltrilotris(methylene phosphonic acid), sodium salt (Nitriloths(methylene))trisphosphonlc acid, sodium salt Phosphonic acid, (nitrilotris-(methylene))tri-, sodium salt Sodium (nitrilotris-(methylene))triphosphonate Sodium aminotris(melhyl-enephosphonate). 

The capacity to preconcentrate anions has enabled the use of chitosan and its derivatives in modified electrodes, for application in sensor and biosensor electrochemistry [233]. To facilitate improving water solubility of biologically useful chitosan derivatives, N-methylene phosphonic chitosan has been prepared using a one-step reaction that allowed homogeneous modifications [234]. 

Organic phosphorus-containing compounds (mono and dialkyl esters(C2 — Cio) of phosphoric acid, hydroxyethylidene-diphosphonic acid, nitrile-tris (methylene phosphonic acid) are mainly used as ingredients of polymer coatings. They are related to Cl of the anodic-passivating type [63]. 

Phosphorus-containing compounds provide useful substrates for ozonolysis reactions as well and can provide several products depending on the reaction workup. Several biological uses exist for -amino-a-hydroxy phosphonic acid derivatives and they can be readily prepared by ozonolysis of Al-(ethoxycarbonyl)-/3-amino-Q -methylene phosphonic esters after reductive workup with sodium borohydride (eq 54). When the reaction mixture is treated with sodium hydroxide in MeOH, an anomalous ozonolysis reaction occurs and cleavage of the methylene as well as the carbon-phosphorus bond occurs to yield (V-(ethoxycarbonyl)-a-amino methyl carboxylic esters. 

As discussed previously, only chelates with a slow exchange rate remain stable in vivo. Indium-113m chelates with EDTA and DTPA have been utilized for the detection of brain tumors and for the study of renal funcions (26.27). Indium-113m chelates with ethylenediamine tetra(methylene phosphonic acid) (EDTMP) and diethylenetriamine penta(methylene phosphonic acid) (DTPMP) have been utilized to study bone tumors (28. 2Q). These agents also have promise for the detection of myocardial infarcts (3il). 

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