Potassium 0,0-diethyl

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

Phenyl tellurium Bis[diethyldithiocarbamate] 0,0-Diethyl Dithiophosphate To a solution of 1.91 g (4.0 mmol) of phenyl tellurium bis[diethyldithiocarbamale] chloride in dichloromethane are added 0.90 g (4.0 mmol) of potassium 0,0-diethyl dithiophosphate. The mixture is stirred for 2 h and then filtered. The filtrate is taken to dryness. The yellow residue is recrystallized from dichloromethane/hexane by slow evaporation m.p. 149-151° (dec.). 

Potassium cyanide, 56, 20 Potassium diethyl phosphite, 58, 135, 138 Potassium 1,1,1,3,3,3-hexafluoro-2-phenyl-... 

A cation arriving with a nncleophilic anion is another important factor. The nucleophile can attack the substrate in the form of a free ion or an ionic pair. As a rule, lithium salts are less reactive than sodium and potassium salts. Russell and Mndryk (1982) reported several examples of this. The sodium salt of ethyl acetylacetate reacts with 2-nitro-2-chloropropane in DMF yielding ethyl 2-(wo-propylidene) acetylacetate. Under the same conditions, the lithium salt does not react at all. Potassium diethyl phosphite interacts with l-methyl-l-nitro-l-(4-toluylsulfonyl)propane in THF and gives diethyl 1-methyl-l-nitro-l-phosphite. The lithinm salt of the same reactant does not react with the same substrate in the same solvent. 

Commercial iodobenzene is dried over molecular sieves. Use of ratios of potassium diethyl phosphite to iodobenzene smaller than 2 1 gives lower yields. Bromobenzene is much less reactive than iodobenzene and gives poor yields by this procedure. 

Potassium diethyl phosphite Phosphorous acid, diethyl ester, potassium salt (8,9) (54058-00-3)... 

Potassium cyanide, 56, 20 Potassium diethyl phosphite, 58, 135, 138 Potassium 1,1,1,3,3,3-hexafluoro-2-phenyl-2 propanolate, 57, 22 Potassium iodide, 55, 71 Potassium permanganate, 55,68,58,47, 52 Potassium p-toluenesulfinate, 57, 8 /-Proline, iV-benzyloxycarbonyl-3-hy-droxy-, 56, 89... 

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 ... 

Kornblum and coworkers31a have determined the quantum yield for the ET substitution reactions of / -nitrocumyl chloride with azide ions (3.5) and quinuclidine (6000). Furthermore, by studying the wavelength dependence of the quantum yields, they have obtained evidence that photochemical initiation proceeds by means of a charge-transfer complex. Similar results have been obtained in the reaction of acetone enolate ion with Phi and PhBr in DMSO, whereas other mechanisms are in competition when Phi reacts with potassium diethyl phosphite3115. 

Acceleration by KI in the substitution reaction of aryl halides with potassium diethyl phosphite or with the 2-naphthoxide ion has also been explained on the basis of an ET through the exciplex of the charge-transfer complex formed between the aryl halide and the iodide ions34a. It has also been reported that iodide ions catalysed the photostimulated reaction of bromoarenes with diethyl phosphite ion34b. 

Fig. 30 Experimental and simulated cyclic voltammograms of the electrochemical inducement of the substitution of chloride in 4-chlorobenzonitrile by potassium diethyl phosphite (0.663 M) in liquid NH at — 40°C. (Saveant, 1980)...

The stabilized a-substituted cyanomethylphosphonate carbanion resulting from the addition of potassium diethyl cyanomethylphosphonate to one equivalent of acrylonitrile in THF/HMPA appears to be a useful reagent in Homer-Wadsworth-Emmons olefination reaction. Thus, the reaction with aromatic aldehydes is completely stereoselective and produces ( )-l-aryl-2,4-dicyano-1-butenes in high yields (71-83%, Scheme 6.34).- ... 

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%). ... 

Ethyl 2-iodobenzoate reacts with potassium diethyl phosphite in liquid ammonia under irradiation in a Bunnett-type reaction to produce the coupling product in 64% yield (Scheme 8.41). ° ... 

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... 

From ethyl-potassium diethyl-malonate a substance of the composition CnH 0, which differs from the expected tetraethyl-succinic acid by C,H was obtained. The nature of this body has not yet been determined. 

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). 

Absolute diethyl ether. The chief impurities in commercial ether (sp. gr. 0- 720) are water, ethyl alcohol, and, in samples which have been exposed to the air and light for some time, ethyl peroxide. The presence of peroxides may be detected either by the liberation of iodine (brown colouration or blue colouration with starch solution) when a small sample is shaken with an equal volume of 2 per cent, potassium iodide solution and a few drops of dilute hydrochloric acid, or by carrying out the perchromio acid test of inorganic analysis with potassium dichromate solution acidified with dilute sulphuric acid. The peroxides may be removed by shaking with a concentrated solution of a ferrous salt, say, 6-10 g. of ferrous salt (s 10-20 ml. of the prepared concentrated solution) to 1 litre of ether. The concentrated solution of ferrous salt is prepared either from 60 g. of crystallised ferrous sulphate, 6 ml. of concentrated sulphuric acid and 110 ml. of water or from 100 g. of crystallised ferrous chloride, 42 ml. of concentrated hydiochloric acid and 85 ml. of water. Peroxides may also be removed by shaking with an aqueous solution of sodium sulphite (for the removal with stannous chloride, see Section VI,12). 

Hexamethylene glycol, HO(CH2)gOH. Use 60 g. of sodium, 81 g. of diethyl adipate (Sections 111,99 and III,100) and 600 ml. of super-d ethyl alcohol. All other experimental detaUs, including amounts of water, hydrochloric acid and potassium carbonate, are identical with those for Telramelhylene Glycol. The yield of hexamethylene glycol, b.p. 146-149°/ 7 mm., is 30 g. The glycol may also be isolated by continuous extraction with ether or benzene. 

CAUTION. Ethers that have been stored for long periods, particularly in partly-filled bottles, frequently contain small quantities of highly explosive peroxides. The presence of peroxides may be detected either by the per-chromic acid test of qualitative inorganic analysis (addition of an acidified solution of potassium dichromate) or by the liberation of iodine from acidified potassium iodide solution (compare Section 11,47,7). The peroxides are nonvolatile and may accumulate in the flask during the distillation of the ether the residue is explosive and may detonate, when distilled, with sufficient violence to shatter the apparatus and cause serious personal injury. If peroxides are found, they must first be removed by treatment with acidified ferrous sulphate solution (Section 11,47,7) or with sodium sulphite solution or with stannous chloride solution (Section VI, 12). The common extraction solvents diethyl ether and di-tso-propyl ether are particularly prone to the formation of peroxides. 

The condensation of aldehydes and ketones with succinic esters in the presence of sodium ethoxide is known as the Stobbe condensation. The reaction with sodium ethoxide is comparatively slow and a httlo reduction of the ketonic compound to the carbinol usually occurs a shorter reaction time and a better yield is generally obtained with the more powerful condensing agent potassium ieri.-butoxide or with sodium hydride. Thus benzophenone condenses with diethyl succinate in the presence of potassium [Pg.919]

To a solution of 0.30 mol of ethyllithium (note 1) in about 270 ml of diethyl ether (see Chapter II, Exp. 1) v/as added 0.30 mol of methoxyallene at -20°C (see Chapter IV, Exp. 4) at a rate such that the temperature could be kept between -15 and -2Q°C. Fifteen minutes later a mixture of 0.27 mol of >z-butyl bromide and 100 ml of pure, dry HMPT ivas added in 5 min with efficient cooling, so that the temperature of the reaction mixture remained below 0°C. The cooling bath was then removed and the temperature was allowed to rise. After 4 h the brown reaction mixture was poured into 200 ml of ice-water. The aqueous layer was extracted twice with diethyl ether. The combined solutions were washed with concentrated ammonium chloride solution (which had been made slightly alkaline by addition of a few millilitres of aqueous ammonia, note 2) and dried over potassium carbonate. After addition of a small amount (2-5 ml) of... 

The aqueous layer was extracted with diethyl ether. The combined ethereal solutions were dried over potassium carbonate, after which the greater part of the diethyl ether was distilled off at normal pressure through a 40-cm Vigreux column (bath temperature < 90°C). Careful distillation of the remaining liquid afforded the bis-ether, b.p. 47-49°C/18 mmHg, Op 1.4469, in 78% yield. 

A solution of 0.10 mol of lithiated methoxyallene in about 70 ml of hexane and 50 ml of THF (see Chapter II, Exp. 15) was cooled to -40°C. Ory, pure acetone (0.12 mol) was added dropwise during 10 min, while keeping the temperature at about -30°. Five minutes after the addition 100 ml of saturated NHi,Cl solution, to which 5 ml of aqueous ammonia had been added (note 1), were run in with vigorous stirring. The product was extracted three times with diethyl ether. The combined organic solutions were dried over potassium carbonate and subsequently... 

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