Phosphonic acid esters mixed

Mixed phosphonate acid esters can also be prepared from alkylphosphonate monoesters, although here the activation is believed occur at the alcohol.57... 

Hydroxyalkyl)phosphonic acids, and also the related phosphinic acids, are normally obtained from hydrogen phosphonates and aldehydes or ketones. The reactions between perfluoroacetone and mixed dialkyl hydrogen phosphonates are noteworthy in that the expected products (129) may be accompanied by the phosphoric triesters (130). Trimethylsilyl alkylene P(III) triesters (131) are also useful starting materials when acted upon by aromatic aldehydes or by (1-oxoalkyl)phosphonic acid esters, the initial... 

The derivatized layered tetravalent metal phosphonates have proven to be a particularly apt example on which to test many of our hypotheses regarding planar bulk arrays of anchored organics. They are relatively easily prepared, providing the phosphonic acid or ester is available, and they provide for a site area which is perfect for nearly close-packed coverage. We have made substantial progress in the detailed characterization of their physical and chemical properties, especially in the areas of crystallinity, surface area and micropore behavior, mixed component phases, and in heterogenization of catalytic sites. 

Alkyl ethers of dialkyl (hydroxymethyl)phosphonic acid have been obtained by a modified Arbuzov procedure in the presence of BF3 Et20, triethyl phosphite reacts with the formals ROCH20Ar according to Scheme 16 the reactions are best carried out in the presence of TiCl4 at -78 °C, but the Lewis acid catalyst and the experimental conditions have to be chosen carefully, otherwise mixed alkyl aryl esters are produced. Boron trifluoride etherate also catalyses the interaction of acetals of 4-substituted benzaldehydes with triethyl phosphite to give diethyl (a-alkoxybenzyl)phosphonates. Both aliphatic and aromatic aldehydes are reported to react with trialkyl phosphites at 100 °C to give the ethers 204 ... 

Monoalkyl esters of the same acid likewise decompose under acidic conditions to give benzonitrile and monoalkyl metaphosphates. The nature of the solvent in which degradation occurs can have a profound effect on the course of such degradation the predominantly ( )-oximes from the mono-2,2,2-trihaloethyl esters 121 and 122 of [a-(hydroxyimino)benzyl]phosphonic acid, as their anions, lose benzonitrile in boiling ethanol or propan-2-ol and yield mixed phosphodiesters 124 (R = Et or Pr ) ( )-(121) does... 

The cathodic electrolysis of mixtures of alcohols and dialkyl methyl (or phenyl)phosphonates in the presence of tetraethylammonium perchlorate in acetonitrile yields mixed esters of the corresponding phosphonic acids. The yields and... 

MixedPhosphona.te Esters. Unsaturated, mixed phosphonate esters have been prepared from monoesters of 1,4-cyclohexanedimethanol and unsaturated dicarboxyhc acids. Eor example, maleic anhydride reacts with this diol to form the maleate, which is treated with benzenephosphonic acid to yield an unsaturated product. These esters have been used as flame-retardant additives for thermoplastic and thermosetting resias (97). 

More recent developments in the field of the Pirkle-type CSPs are the mixed r-donor/ r-acceptor phases such as the Whelk-Of and the Whelk-02 phases.The Whelk-Of is useful for the separation of underiva-tized enantiomers from a number of families, including amides, epoxides, esters, ureas, carbamates, ethers, aziridines, phosphonates, aldehydes, ketones, carboxylic acids, alcohols and non-steroidal anti-inflammatory drugs.It has been used for the separation of warfarin, aryl-amides,aryl-epoxides and aryl-sulphoxides. The phase has broader applicability than the original Pirkle phases. The broad versatility observed on this phase compares with the polysaccharide-derived CSPs... 

Synthesis of Phosphoric Acids and their Derivatives. - Among various approaches to phosphate esters the phosphorylation of phenols with dialkyl cyanophosphonate and the synthesis of triaryl phosphates under phase-transfer conditions are worthy of mention. Mixed trialkyl phosphates are also reported to be formed by brief cathodic electrolysis of the reaction of dialkyl phosphonates with aromatic aldehydes and ketones, presumably by rearrangement of the initial a-hydroxy compounds. Further reports have appeared of the generation of metaphosphates by various methods. The synthesis of analogues 1 of famesyl pyrophosphate which incorporate photoactive esters has been reported both compounds are competitive inhibitors of farnesyl transferase. 

Many inhibitors may be present in biological samples or in buffers currently used for EIA. Pi is a competitive inhibitor of the enzyme and forms an intermediate with the enzyme which is indistinguishable from the intermediate formed during catalysis of the hydrolysis of phosphate esters (Caswell and Caplow, 1980). The K, (i.e. the for Pi) is lower than the for the substrate, typically KijK, = 0.3, i.e. a lower concentration of Pi than of the substrate is required to half-saturate the enzyme. Arsenate is a stronger competitive inhibitor than Pi, whereas phosphonates are weaker. Metal chelating products (EDTA, cysteine, thioglycolic acid) are also important inhibitors. Many amino acids show a mixed competitive or uncompetitive inhibition (Fernley, 1971). 

Pudovik, A.N., and Khlyupina, N.L, New method of synthesis of esters of phosphonic and thiophos-phonic acids. Part 25. Addition of mixed dialkyl phosphites, dialkyl thiophosphites, and diallyl phosphite to unsaturated compounds, Zh. Obshch. Khim., 26, 1672, 1956 Chem. Abstr., 51, 3439f, 1957. 

The phosphonomethylation of dialkyl [(alkylamino)alkyl]phosphonates (238) in the customary way yields products with mixed phosphoryl functions, e.g. the acids 239 or their esters 240 and 241 are obtained by the phosphonomethylation of alkyl[(alkylamino)-methyljphosphinic acids ... 

As in the case of ester hydrolysis, mixed phosphonates consisting of acidic and hydrophobic functions accelerated the esterification of acetic acid when compared to catalysts without the hydrophobic function (169,227). 

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