DIETHYL PHENYLPHOSPHONATE

Preparation of diethyl phenylphosphonate — Reaction of an aryl halide with a dialkyl phosphite in the presence of a Pd(0) catalyst and a tertiary amine... 

Diethyl phenylphosphonate is appreciably soluble in water. Therefore excessive amounts of water should be avoided. 

Diethyl phenylphosphonate Phosphonic acid, phenyl-, diethyl ester (8,9) (1754-49-0)... 

Nitrogen heterocycles continue to be valuable reagents and provide new synthetic approaches such as NITRONES FOR INTRAMOLECULAR -1,3 - DIPOLAR CYCLOADDITIONS HEXAHYDRO-1,3,3,6-TETRAMETHYL-2,l-BENZISOX AZOLINE. Substituting on a pyrrolidine can be accomplished by using NUCLEOPHILIC a - sec - AM IN O ALKYL ATION 2-(DI-PHENYLHYDROXYMETHYL)PYRROLIDINE. Arene oxides have considerable importance for cancer studies, and the example ARENE OXIDE SYNTHESIS PHENANTHRENE 9,10-OXIDE has been included. An aromatic reaction illustrates RADICAL ANION ARYLATION DIETHYL PHENYLPHOSPHONATE. 

A comparison of the suitability of solvents for use in Srn 1 reactions was made in benzenoid systems46 and in heteroaromatic systems.47 The marked dependence of solvent effect on the nature of the aromatic substrate, the nucleophile, its counterion and the temperature at which the reaction is carried out, however, often make comparisons difficult. Bunnett and coworkers46 chose to study the reaction of iodoben-zene with potassium diethyl phosphite, sodium benzenethiolate, the potassium enolate of acetone, and lithium r-butylamide. From extensive data based on the reactions with K+ (EtO)2PO (an extremely reactive nucleophile in Srn 1 reactions and a relatively weak base) the solvents of choice (based on yields of diethyl phenylphosphonate, given in parentheses) were found to be liquid ammonia (96%), acetonitrile (94%), r-butyl alcohol (74%), DMSO (68%), DMF (63%), DME (56%) and DMA (53%). The powerful dipolar aprotic solvents HMPA (4%), sulfolane (20%) and NMP (10%) were found not to be suitable. A similar but more discriminating trend was found in reactions of iodobenzene with the other nucleophilic salts listed above.46 Nearly comparable suitability of liquid ammonia and DMSO have been found with other substrate/nucleophile combinations. For example, the reaction of p-iodotoluene with Ph2P (equation (14) gives 89% and 78% isolated yields (of the corresponding phosphine oxide) in liquid ammonia and DMSO respectively.4 ... 

On completion of the triethyl phosphite addition and cessation of ethyl iodide evolution (less than 30 min after completion of the addition, up to 3.8 mL, 7.6 g, 99% is evolved, along with some triethyl phosphite) cool the reaction mixture and set up for fractional distillation. Distil the product at vacuum-pump pressure, discarding any low boiling fore-run, and collect pure diethyl phenylphosphonate, 16 (b.p. 94-101°C, 0.1 mmHg, 9.45 g, 90 %), as a liquid. 

In the presence of [PdMe2(PMePh2)3] diethyl benzoylphosphonate is degraded during minutes and with quantitative yield, into diethyl phenylphosphonate (l-oxoalkyl)phosphonic esters suffer a similar fate but the process may take several hours under the same conditions. When mixtures of aroylphosphonic diesters and esters of (l-oxoalkyl)phosphonic acids are brought into contact with the... 

Bunnett, J.F., and Weiss, R.H., Radical anion arylation. Diethyl phenylphosphonate (phosphonic acid, phenyl-diethyl ester), Org. Synth., 58, 134, 1978 Org. Synth. Coll. Vol. VI, 451, 1988. 

Curiously, the sodium salt of diethyl hydrogenphosphonate condensed in an exothermic reaction with o-fluorobromobenzene in the presence of magnesium in tetrahydrofuran (67). Diethyl phenylphosphonate (41 %) was considered to result from attack of benzyne on the phosphorus compound since triphenylene was also isolated. 

The monoaryl esters of [A-(phenyacetyl)amino]methyl phosphonic acid hydrolyse at much faster rates under either alkaline 566 or acidic 567 conditions than analogues which lack the acylamino or even acyl substituents, although the potential intermediate 568 could not be detected A comparison of the rates of hydrolysis of diethyl (aminomethyl)phos-phonates with the rates for diethyl phenylphosphonate and tetraethyl methylenebisphos-... 

To a flask equipped with a dropping funnel and refluxing condenser were added 10 g iodobenzene and 10 mg nickel tetra(triethyl phosphite). When the solution was heated to 160°C, 9.37 g triethyl phosphite (56.4 mmol) was added in small portions ( 5 drops). The solution became deep red upon each addition of phosphite. The color rapidly faded to yellow, ethyl iodide was distilled into a cold trap, and an exotherm was observed. When the reaction was completed (monitored by GLC), 9.88 g diethyl phenylphosphonate was obtained via distillation at 0.1 mmHg, b.p. 94-101°C, in a yield of 94%. 

Diethyl phenylphosphonate added dropwise with ice-cooling under Ng to phenyl-dichlorophosphine in dry ether, and the product isolated after 2 hrs. ethyl phenylphosphonochloridate. Y 74%. F. e. s. E. Steininger, B. 95, 2993 (1962). 

The first experimental proof of the mechanism of the silylation in the McKenna reaction has been presented by Blazewska. The reaction of a model compound isotopically enriched diethyl phenylphosphonates (644) (P= 0 or P= 0) showed that reaction in acetonitrile proceeded via an attack of P=0 ojgrgen on the silicon atom in hromotrimethylsilane (Scheme 188). The change in the phosphorus-o g gen hond order was directly detected using P and NMR spectroscopy. 

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