Isopropyl phosphonic acid

C 1H15NO2S 3339-36-4) see. Tiemoniuin iodide (2-oxononyl)phosphonic acid dimethyl ester (C11H23O4P 57497-25-9) see Unoprostone isopropyl (S)-4-[[4-[(2-oxo-4-oxazolidinyl)methyl]phenyl]hydrazo-no]butanenitrile... 

Once inside the body, diisopropyl methylphosphonate is rapidly converted to isopropyl methyl-phosphonic acid (IMPA), which is rapidly cleared from the blood. Laboratory tests can determine the amount of IMP A in the blood or urine. However, because IMPA leaves the body rapidly, these tests are useful only for recent exposure. It is helpful for your doctor to know whether there are other chemicals to which you have been exposed. See Chapters 2 and 6 for more information. 

Hoskin FCG. 1956. Some observations concerning the biochemical inertness of methyl phosphonic and isopropyl methylphosphonic acids. Can J Biochem Physiol 34 743-746. 

Phosphonates, methyl-, diaryl, reaction with cy-cloheptaamylose, 23 240,241 Phosphonic acid, methyl-, isopropyl p -... 

Functionalized polymers are of interest in a variety of applications including but not limited to fire retardants, selective sorption resins, chromatography media, controlled release devices and phase transfer catalysts. This research has been conducted in an effort to functionalize a polymer with a variety of different reactive sites for use in membrane applications. These membranes are to be used for the specific separation and removal of metal ions of interest. A porous support was used to obtain membranes of a specified thickness with the desired mechanical stability. The monomer employed in this study was vinylbenzyl chloride, and it was lightly crosslinked with divinylbenzene in a photopolymerization. Specific ligands incorporated into the membrane film include dimethyl phosphonate esters, isopropyl phosphonate esters, phosphonic acid, and triethyl ammonium chloride groups. Most of the functionalization reactions were conducted with the solid membrane and liquid reactants, however, the vinylbenzyl chloride monomer was transformed to vinylbenzyl triethyl ammonium chloride prior to polymerization in some cases. The reaction conditions and analysis tools for uniformly derivatizing the crosslinked vinylbenzyl chloride / divinyl benzene films are presented in detail. 

This method is compatible with many functional groups and shows considerable selectivity. Phosphonic acid esters may be cleaved in the presence of carboxylic acid esters, and phosphonate methyl esters are cleaved approximately 25 times faster than the isopropyl esters. For example, the phosphonate methyl ester of the hexapeptide analogue 78 was cleaved with TMSBr to give the aspartic peptidase inhibitor 79 in 64% yield (Scheme 28). 66 ... 

The simultaneous and selective protection of the two equatorial hydroxyl groups in methyl dihydroquinate [11L1, Scheme 3.111 j as the butane-2,3-diace-tal 111 2 was a key strategic feature in a synthesis of inhibitors of 3-dehydroqui-nate synthase.205 Later in the synthesis, deprotection of intermediate 111.4 required three steps (a) hydrolysis of the trimethylsilyl ether and the butane-2,3-diacetal with trifluoroacetic acid (b) cleavage of the isopropyl phosphonate with bromotrimethylsilane and (c) hydrolysis of the methyl ester with aqueous sodium hydroxide. Compound 111 1 has also been used in the synthesis of inhibitors 3-dehydroquinate dehydratase206 and influenza neuraminadase207-208 as well as shikimic add derivatives.209 210... 

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. 

A number of acylphosphonic acids are of interest for their biological activity, or as intermediates in syntheses of potentially bioactive phosphonic acids [7, 34, 48 - 50]. In many cases, they are most conveniently prepared by hydrolysis of the corresponding esters. Due to the presence of the keto function, acid hydrolysis (heating in aqueous HCl) is generally not a practical method to achieve this. Silyldealkylation of methyl-, ethyl- or isopropyl phosphonates with BTMS, followed by very mild hydrolysis is normally compatible with acyl and other sensitive functionalities [7,34,48]. 

US EPA (2005b). Isopropyl methyl phosphonic acid. IRIS online database http //www.epa.gov/ iriswebp/iris/index.html. Washington, DC US Environmental Protection Agency, retrieved April 18, 2005. 

The alkylation reaction occurred easily with both primary and secondary halides. When R = Et in the phosphonate carbanion, the alkylated phosphonate suffers partial dealkylation to 0"(R0)P(0)GFR CCX)Et by SN2 attack of the lithium halide produced in the reaction. This side-reaction can be easily suppressed by use of the corresponding isopropyl phosphonate carbanion. Thus, this straightforward alkylation of (3) appeared promising as an entry to a-fluoroesters. Alkylation occurred only at carbon and the absence of hydrogen at the a-carbon in the phosphonate precluded any transylidation process, thus allowing total utility of the phosphonate carbanion only in the desired alkylation reaction without concomitant loss of the phosphonate carbanion in acid-base side-reactions. 

The early literature describes examples of elimination reactions of a rather forcing nature which have not been explored further. For example, the elimination of HCl from (2-chloroethyl)phosphonic dichloride occurs over BaCl2 at 330 and dechlorination of (l,2-dichloroethyl)phosphonic diesters occurs on heating with zinc dust. Dehydrochlorination of a (2-chloroalkyl)phosphonic acid occurs on simple pyrolysis but the preferred procedure consists in the treatment of the acid diester with Et3N in warm benzene, a procedure also used for analogous (2-chloroethyl)phosphinic esters ". The dehydro-halogenation of isopropyl (2-haloethyl)phenylphosphinate by a chiral tertiary amine, such as quinine, quinidine, 1 -phenylethylamine or A-methylephedrine, in a less than equivalent quantity, affords an enrichment of one enantiomer of the ethenylphenylphosphinic... 

New developments in the synthesis of a-hydroxy phosphonic acids and their derivatives have concentrated on their asymmetric formation. The chiral phosphonic diamides (629) (in which R = isopropyl, 2,2-dimethylpropyl, or benzyl or a derivative thereof) in either racemic or optically active forms were converted into their anions and allowed to react with aldehydes to give the products (630) the diastereoisomeric composition of the latter could be ascertained by the use of P NMR spectroscopy, and after acidic hydrolysis and subsequent methylation (diazomethane) it was possible to isolate optically active forms of the dimethyl esters of (l-hydroxyalkyl)phos-phonic acids, the (/ ,R)-diamide giving rise to the (5)-acids as their esters. The best results were achieved when R = Bu CFl2, and enantiomeric excesses were generally above 85% . 

Notable exceptions to this generalization, apart from the lack of activity towards derivatives of the phosphonic acids, are isopropyl- and / r/-butyl-phosphonic acids and ben-zylphosphonic acid (2-methylpropyl)phosphonic acid is cleaved to give very low yields of 2-methylpropene and 2-methylpropane Isotopically labelled (carbon or hydrogen) methylphosphonic acid affords methane possessing the identical distribution of the... 

This compound is a dibromo derivative of phosphonic acid, with an isopropyl group replacing a hydrogen, therefore its name is isopropyl phosphonic dibromide. 

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-... 

In the same study, droplets of GB deposited on the snow surface were removed by a combination of evaporation, which was dependent on wind speed, and hydrolysis. Within 5 hr, approximately 55% was removed by evaporation and 15% was removed by hydrolysis. Newly fallen snow protected droplets from evaporation. However, 2 and 4 wk after being sprayed on the snow, GB was still present. The hydrolysis product, isopropyl methylphosphonic acid, as well as the impurities diisopropyl methylphosphonate and dipinacolyl methyl-phosphonate were present, even after 4 wk. 

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).

Fig. 2 HPLC ICP-MS single ion monitoring (SIM) from a standard mixture of three alkyl phosphonic acids at a concentration of lOOng/ml each 1) methylphosphonic acid (MPA) 2) ethyl methylphosphonic acid (EMPA) 3) isopropyl methylphosphonic add (iPrMPA).

Fig. 3 Reversed-phase HPLC-MS/MS chromatogram using formic acid in the mobile phase and an Atlantis dC18 column. The standard mixture of alkyl phosphonic acids with a concentration of 10 p,g/ml each was detected using multiple reaction monitoring (MRM) 1) methylphosphonic acid (MPA, miz 96.8 78.7) 2) ethyl methylphosphonic acid (EMPA, mIz 125 96.8) 3) C>-elhyl A,A-dimethylamidophosphoric add (EDMAPA, miz 154.2—>126) 4) isopropyl methylphosphonic acid (iPrMPA, nJz 139.1 %.8) 5) pinacolyl methylphosphonic acid (PinMPA, miz 181.3- 96.8) 6) diisopropyl methylphosphonic add (DiPrMPA, mk 181.3 139.1). See the text for further chromatogr hic details and the MS/MS conditions used.

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