Phosphonic acids diphenyl esters

Synonyms Diphenyl phosphonate DPP Phosphonic acid, diphenyl ester... 

Phosphonic acid, (phthalimidomethyl)-, diethyl ester, 65, 119 Phosphorazidic acid, diphenyl ester (26386-88-9), 68,1 Phosphoric triamide, hexamethyl- (680-31-9), 66, 51, 94 Phosphorodichloridic acid, 2-chloroethyl ester, 65, 68 Phosphorous acid, triethyl ester, 65, 108.119 Phosphorus oxychloride, 66,173, 176 67,1 68, 41,162 Phosphorus tribromide (7789-60-8), 67, 210 Phthalimide, N-(bromoethyl)-, 65, 119 Phthalimide, N-(hydroxymethyl)-, 65,119 Pig liver esterase, 69, 20... 

Trimethylsilyl esters of tris(thio)phosphonic acids 2070 are readily oxidized by DMSO in toluene at -30 °C to give the dimeric tetra(thia)diaphosphorinanes 2071 and HMDSO 7 [208] (cf. also the oxidation of silylated thiophenol via 2055 to diphenyl disulfide). The polymeric Se02 is depolymerized and activated by reaction with trimethylsilyl polyphosphate 195 to give the corresponding modified polymer... 

Scheme (17) illustrates the synthesis of the diphenyl ester (118) of (l-amino-2-propenyl)phosphonic acid (119), an... 

A series of 1-aminoalkanediphosphonic acids has been reported by the treatment of the N-phenylthiourea derivatives of a>-diethoxyphos-phinoylaldehydes with triphenyl phosphite.343 This constitutes an approach toward the analogues of aspartic and glutamic acid in which both carboxylate sites have been replaced by phosphonic acid functions. A similar approach has also been reported to be of use for the preparation of (diphenyl ester) phosphonate analogues of ornithine, lysine, and homolysine.344345... 

The reaction of 6-methylpyridine-3-carboxylic acid methyl ester with N,0-dimethylhydroxylamine and isopropyl-magnesium chloride in toluene gives the N-methoxyamide derivative (x), which is reduced with diisobutyl aluminium hydride (DIBAL) to afford 6-methylpyridine-3-carbaldehyde (xi). The reaction of the aldehyde (xi) with a phosphite provides the diphenyl phosphonate derivative, which is condensed with 4-(methylsulfonyl)benzaldehyde in the presence of potassium fe/f-butoxide in HF to yield the enimine (xii). Finally, this compound is hydrolyzed with HCI to yield the ketosulfone (ix). 

Because of the possibility of racemization during the transesterification reaction (strong basic conditions) alternative methods are reported. These include transesterification in the presence of the KF/18-crown-6 ether 461 or the use of titanium tetraalkoxides. 471 The methods are efficient and represent a route to any required dialkyl ester using diphenyl esters as starting materials. Diphenyl groups can also be removed by hydrogenation in the presence of platinum dioxide (Adams catalyst) to provide the free phosphonic acid moiety directly)46 ... 

The methodology of the catalytic asymmetric aldol reaction has been further extended to the aldol-type condensation of (isocyanomethyl)phosphonates (12) with aldehydes, providing a useful method for the synthesis of optically active (l-aminoalkyl)phosphonic acids, which are a class of biologically interesting phosphorous analogs of a-amino acids (Scheme 8B1.6) [21,22], Higher enantioselectivity and reactivity are obtained with diphenyl ester 12b than with diethyl ester 12a (Table 8B1.6). 

SYNS DIPHENYL METHANEPHOSPHONATE DIPHENYL METHYLPHOSPHONATE PHOSPHONIC ACID, METHYL-, DIPHENYL ESTER SAFETY PROFILE A poison by ingestion. When heated to decomposition it emits toxic vapors of POx. 

PHOSPHONIC ACID, 1-HYDROXY-l.l-ETHANEDIYL ESTER see HKS780 PHOSPHONIC ACID, (1-HYDROXYETHYLIDENE)BIS- see HKS780 PHOSPHONIC ACID, METHYL-, DIPHENYL ESTER see MDQ825... 

PNOCi2H,2, Phosphinic amide, diphenyl-lanthanoid complexes, 23 180 PNOSiCi2Hi Phosphinimidic acid, P-methyl-P-phenyl-N-(trimethylsilyl)-2,2,2-trifluoroethyI ester, 25 72 PN04CsH,g, Phosphonic acid, [(N,N-di-diethyIcarbamoyl)methylJ-, dimethyl ester, 24 101... 

General method for preparation of diphenyl esters of Gong-chain alkyl)phosphonic acids Equivalent amounts of the alcohol and triphenyl phosphite, together with 10 moles-% of sodium iodide, are placed in a flaskfitted with a thermometer, gas-inlet tube, stirrer, and distillation head water at about 50° is circulated through the attached condenser to prevent crystallization of the phenol. Nitrogen is led into the flask while the mixture is heated at the required temperature by a radiant heater until no more phenol distils (about 20 h). The remaining material is distilled at < 0.05 mm and the distillate is taken up in ether. The ethereal solution is washed with 2N-sodium hydroxide solution, dried and evaporated, and the residue is redistilled. 

Amino Acids and Peptides. - Wasserman s method of one-carbon homologation of carboxylic acids to give a-ketocarboxylates involves reaction with cyanomethylenetriphenyl-phosphorane followed by ozone (Scheme 24) and has been used as a key step in a chemo-enzymatic synthesis of isotopically labelled L-valine, L-isoleucine, and o/fo-isoleucine. Alkylation of the carbanion derived from the imino-substituted methylphosphonate diphenyl ester (186) with indol-3-ylmethyl bromide followed by appropriate deprotection has been used to prepare the phosphonate analogue (187) of tryptophan (Scheme 25). The deprotected analogue (188) and derived peptides show activity as inhibitors of chymotrypsin. Two approaches to solid phase Wadsworth-Enunons reactions which have applications in combinatorial chemistry have been reported. In one diethylphosphonoacetamide is bound to PEG-PAL resin via a peptide link, while... 

The Wittig reaction involves the interaction of an aldehyde or ketone with a phosphorus-containing carbanionic species, in which the phosphorus is bonded directly to the carbanionic site. At the time of discovery of the reaction, that specification described the triphenylphosphonium alkylides 343 later developments employed the anions from tert-phosphine oxides, the use of which has been described elsewhere in this series and also from a wide variety of phosphonic and phosphinic esters. This latter application will be considered more fully in Chapter 6. An early application of the reaction to the synthesis of alkenephosphonic acids, and which involved an ylide, employed the stable compound 344, generated from 345 by the action of a strong base. Reactions between 344 and aliphatic or aromatic aldehydes at 100 °C in toluene or dmso gave the diphenyl esters of (alk-1-enyl)phosphonic acids or (2-arylethenyl)phosphonic acids. ... 

The addition of phosphorous acid to 3,4-dihydroisoquinoline gives 1,2,3,4-tetra-hydroisoquinoline-1-phosphonic acid (192), and that of diphenyl hydrogenphosphonate to 2/f-pyrroline yields the diphenyl ester of Pro (193). ... 

Studies on the alkaline hydrolysis of various phosphonic and phosphinic esters have provided information on the electronic or steric effects of substituents and the effects of changes in reaction conditions amongst the substrates so extensively examined are the O-aryl esters of dimethylphosphinothioic acid (552) esters of diphenylphosphinic acid and O-aryfand S -aryf esters of diphenylphosphinothioic acid (553 Z, Y = O or S). Other studies have concentrated on aryl esters of diaryIphosphinic acids (554) , and the effects of the stepwise replacement of P-Me by P-Ph in esters of dimethyl-, methylphenyl- and diphenyl-phosphinic acids The esters 555 (R = EtO, R = Me or Ph, R = R = Ph X = SEt or hydrolyse under alkaline conditions faster than do the comparable 5 -(4-substituted-butyl) esters. Comparable steric and electronic influences on the hydrolyses of phosphonic and phosphinic fluorides phosphinic chlo-rides the phosphonothioic chlorides 556 and other phosphonic and phosphinic esters have been noted. Phosphonic and phosphinic halides are prone to undergo halo-gen-exchange reactions, a process which, in general, is faster for derivatives of phosphonic than for those of phosphonothioic and phosphonoselenoic acids, and to be particularly important for acid fluorides . ... 

PCgH,, Phosphonous acid, phenyl-, dimethyl ester, nickel complex, 28 101 OjPCijH, , Phosphinic acid, diphenyl-, tin complex, 29 25... 

Peptides containing a P-terminal aminophosphonic acid have been prepared by coupling protected amino acids with dialkyl or diaryl esters of aminoalkanephosphonic acids or free acids. Protection of the amino phosphonic acid groups is an important step in the phospho-nopeptide synthesis. Aminophosphonates based on the H-phosphonate diesters are used directly for the preparation of phosphonopeptides. Diphenyl aminoalkanephosphonates are attractive starting materials for phosphonopeptide synthesis because they are readily available, and efficient coupling is easily achieved by most methods used in peptide chemistry. 

Holmes, R.R., Day, R.O., Yoshida, Y. and Holmes, J.M., Hydrogen-bonded phosphate-esters - synthesis and structure of imidazole-containing salts of diphenyl phosphate and (trichloromethyl)phosphonic acid, J. Am. Chem. Soc. 114 (5), 1771-1778 (1992). 

Phosphonate ester or phosphonic acid substituents have been additionally evaluated in an attempt to increase the interacting sites with the phosphoric acid doping agent along the polyelectrolyte macromolecular chains. These were strategically located as side groups in a diol monomer which was prepared by a phosphoms-carbon coupling reaction of tetrahydropyranyloxy diprotected 2,5-dibromo-1,4-dihydroxy benzene with diethylphosphite. Either in the phosphonate ester or in the phosphonic acid form the diol was used in polymerizations with the bis (4-fluorophenyl) sulfone or bis(4-fluorophenyl) phenylphosphinoxide as well as with the 2,5-diphenyl-pyridine diol and the tetramethyl-... 

In the synthesis of 6 -deoxyhomonucleoside-6 -phosphonic acids the phosphonate was masked as the diphenyl ester [42]. On transesterification with sodium benzyloxide in dimethyl sulphoxide the dibenzyl ester was formed, and subsequently hydrogenated to give the desired compound (Fig. 6.19). 

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