Potassium diethyl phosphate

Sodium enolates of diethyl 2-oxoalkylphosphonates react with diethyl chlorophosphate to produce enol phosphates. Low-temperature treatment of enol phosphates with tert-BuOK induces the ()-elimination of potassium diethyl phosphate and formation of diethyl 1-alkynylphosphonates in good yields (43-95%, Scheme 7.113). However, the reaction is prone to prototropic isomerization and diethyl 2-oxobutyIphosphonate leads to a mixture of diethyl 1-butynyIphosphonate (43%) and diethyl 2-butynylphosphonate (51%). ... 

As shown in Scheme 18.2, the anion 13 reacts with benzaldehyde to give one of the stilbenes 9 or 10 with high selectivity by a sequence of reactions similar to that observed for the reaction of the ylide 5 with 6 (Scheme 18.1). The intermediate adduct 14 undergoes cyclization to form 15, which then fragments to give the stil-bene and potassium diethyl phosphate (16). 

Hydroxy groups on benzene rings can be replaced by NH2 groups if they are first converted to aryl diethyl phosphates. Treatment of these with KNH2 and potassium... 

HPLC has also been used to determine econazole in plasma21 where the samples were made alkaline with potassium hydroxide and extracted in diethyl ether. The extracts were evaporated to dryness and the residue dissolved in methanol. Chromatography was performed on a Partisil 10 ODS column using a mobile phase consisting of methanol-aqueous potassium dihydrogen phosphate (0.01 M, 70 30, v/v) adjusted to pH 4.5 at a flow rate of 2.0 ml/min. Detection was by UV absorbance at 220 nm and quantitation was by peak height ratio against an internal standard (miconazole). The recovery of econazole from plasma was 84% 9.2, SD., n -25). 

Two examples serve to show the relative usefulness of the Michaelis-Becker and Michaelis-Arbuzov procedures. In the first, 540 (Z = Br) suffers debromination when heated with triethyl phosphite, and 541 was prepared only from 540 (Z = Cl) and sodium or potassium diethyl phosphite . In the second example, the formation, from 542, of the enol phosphate 543 in the Michaelis-Arbuzov case, is obviated by the use of sodium diethyl phosphite when the desired phosphonate 544 was obtained l... 

Sample preparation Vortex 1 mL plasma or urine, 50 (xL 30 ng/mL (plasma) or 15 p,g/mL (urine) IS in 1% acetic acid, 100 p,L 1 M NaOH, and 6 mL diethyl ether for 5 min, centrifuge at 2500 g for 5 min, freeze in dry ice/acetone. Extract the organic layer with 100 (plasma) or 200 (urine) p,L buffer. Freeze in dry ice/acetone, discard organic layer, remove all traces of ether with a stream of nitrogen, thaw, inject a 50 p.L aliquot. (The buffer was 1.7 g potassium dihydrogen phosphate, 1.7 g sodium acetate, and 0.5 g sodium heptanesulfonate in 500 mL water, adjusted to pH 3.5 with acetic acid.)... 

Both primary and secondary alcohols can be converted into the corresponding aldehyde or ketone by a method using allyl diethyl phosphate, as hydrogen acceptor, in combination with either potassium or sodium carbonate and Pd(OAc)2 as catalyst. For example, 2-octanone and cirmamaldehyde have each been synthesized by this route, and in yields of 85 and 90%, respectively. ... 

Similarly, the methiodide was reacted with diethyl (2,2,2-trichloro-ethoxycarbonyl)aminomalonate as a nucleophile to give 118, which was then converted to the amine 119 by deprotection of the 2,2,2-trichloroethoxy-carbonyl group with zinc and potassium dihydrogen phosphate. Dehydrative cyclization of 119 to the azepinoindole 120 was achieved by heating 119 in the presence of a catalytic amount of pyridinium p-toluenesulfonate in dichloromethane. Hydrolysis of 120 with potassium hydroxide in methanol yielded the malonic acid derivative which was then readily decarboxylated on heating in aqueous ethanol to accomplish total syntheses of ( )-cis- and ( )-tranj-clavicipitic acid (84,85) in aratio 3 2 (Scheme 18) (57). 

An amount of enzyme preparation equivalent to 900 mg of wet cells was made up to 25 ml with the above potassium phosphate buffer solution. 150 mg (1.15 mmol) of 5-fluorouracil and 1.0 gram of thymidine (4.12 mmol) were dissolved in 15 ml of the above potassium phosphate buffer solution. The mixture was incubated at 37°C for 18 hours. After this time, enzyme action was stopped by the addition of four volumes of acetone and one volume of peroxide-free diethyl ether. The precipitated solids were removed by filtration, and the filtrate was evaporated under nitrogen at reduced pressure until substantially all volatile organic solvent had been removed. About 20 ml of aqueous solution, essentially free of organic solvent, remained. This solution was diluted to 100 ml with distilled water. 

To a solution of 1.5 mmol of KDA, prepared from potassium lerl-butoxide, diisopropylamine and butyl-lithium, in 7 mL of diethyl ether is added dropwise, under an argon atmosphere, a solution of 0.293 g (1 mmol) of (/ )-2-methoxy-2-phenyl-l-[( )-3-phenyl-2-propenyloxy]propane in 2 mL of diethyl ether at — 100 °C (liquid nitrogen/methanol). After stirring for 5 h the resulting dark-red suspension is treated with a solution of 0.284 g (2 mmol) of iodomethane in 1 mL of diethyl ether. The mixture is stirred until the red color disappears (about 2 h). Then, the bath is removed and 5 mL of phosphate buffer (pH 7) are added, the mixture is extracted with ethyl acetate several times. The extracts are washed with aq NaCl, dried over MgS04, and concentrated. The residue is purified by TLC on silica gel to give (7 )-2-methoxy-2-phenyl-1-[(ii)-3-phenyl-l-butenyloxy]propane yield 0.232 g (75%). This is hydrolyzed to 3-phenylbutanal by treatment with aq perchloric acid (40 %)/diethyl ether. 

Sodium phosphate monobasic [S 9638], sodium phosphate dibasic [S 0876], sodium chloride [S 7653], acetylcholinesterase from Elect-rophorus electricus (Type V-S) [C 2888], potassium chloride [P 3911], 1,2-diaminobenzenedihydrochloride [P 1526], paraoxon (o,o-diethyl o-4-nitrophenyl phosphate) [D 9286], ferrocene carboxylic acid [106887], aniline [A 9880] and acetylthiocholine chloride [A 5751] were purchased from the Sigma Chemical Company (Dorset, UK). Screen-printed transducers were purchased from Gwent Electronic Materials Ltd. (Gwent, Wales, UK). These electrode assemblies comprised a working electrode based on carbon ink doped with cobalt phthalocya-nine, an on board reference electrode (Ag/AgCl) and counter electrode (platinum) (see Fig. 24.1). 

Buffered Tetrahydrofuran. In 1973, Tettamanti et al. [19) described an improved procedure for the extraction, separation and purification of brain gangliosides. In this method, the brain tissue was subjected to homogenization and extraction with buffered [potassium phosphate buffer, pH 6.8) tetrahydrofuran. Following centrifugation, diethyl ether was added and the mixture separated into organic and aqueous phase. The gangliosides, recovered exclusively in the aqueous phase, were then freed of residual phospholipids and other minor contaminants [i.e. peptides)by column chromatography on silica gel.This procedure, as shown by the authors,was superior to the commonly used chloroform/methanol... 

Phenyl tellurium bis[diethyldithiocarbamate] chloride and potassium 0,0-diethyl dithio-phosphate reacted in dichloromethane with exchange of chloride for dithiophosphate2. 

The metabolic and/or hydrolytic products of parathion encountered as residues in the urine include both diethyl phosphoric acid and diethyl phosphorothioic acid, most probably as their salts (potassium or sodium). Derivatization of these residues with diazomethane would result in the formation of three trialkyl phosphate compounds, namely, 0,0-diethyl O-methyl phosphate (DEMMP), 0,0-diethyl 0-methyl phosphoro-thionate (DEMMTP), and 0,0-diethyl S-methyl phosphorothiolate (DEMMPTh). Earlier (15), it had been shown by combined gas chromatography-mass spectrometry and other analytical data that a later-eluting major product ca. 85%) of the methylation of diethyl phosphorothioic acid formed under the conditions of the analytical method was DEMMPTh, and the minor product formed (ca. 15%) was DEMMTP. Accordingly, all three trialkyl phosphates were observed and confirmed by mass spectrometry in the analysis of the human urine extract. Sufficient internal bond energy differences are associated with the isomeric structures DEMMPTh and DEMMTP that qualitatively and quantitatively dissimilar fragmentation patterns are observed for both isomers as can be seen from the mass spectra of these compounds shown in Figure 4. 

Serum proteins have also been fractionated in the phase systems polyethylene glycol/potassium phosphate/water (L4) and diethylene glycol/ diethyl ether/glycerophosphate/water (T6). 

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