Potassium ferf-butoxide, solution

In case of carboxylic acid starting materials, they were first converted into their corresponding acyl chlorides by reacting with oxalyl chloride in dichloromethane. A cooled dichloro-methane solution of an acyl chloride (1 1 mmol) in a 25 mL round bottomed flask was then added with triethylphosphite (1 mmol) drop-wise under stirring, and the reaction mixture was allowed to attain room temperature. On completion of the formation of acyl phosphonate, the reaction mixture was reduced in vacuo, and benzoic acid (2 mmol) was added directly to the residue, followed by benzene. The mixture was stirred to dissolve completely, then hydrazine solution in THF (1.05 mmol) was added drop-wise under rapid stirring. On completion of hydrazone formation, the reaction was flash-frozen and lyophilized. After lyophilization, 1 1 v/v tetrahydrofuran ferf-butanol was added to the flask and stirred to dissolve the solid. Potassium ferf-butoxide solution (3 mmol) in 1 1 v/v tetrahydrofuran ferf-butanol was then added to the stirring solution in one portion. After stirring at room temperature for several hours, the reaction was diluted with ethyl acetate (50 mL), quenched with 1 N HCl (20 mL), washed with saturated sodium bicarbonate (2 x 15 mL), then with brine (15 mL),... 

Oxidation of Diphenylmethane in Basic Solution. Diphenylmethane reacts with an excess of oxygen in the presence of potassium ferf-butoxide in various solvents to produce nearly quantitative yields of benzophenone. In DMSO (80% )-tert-butyl alcohol (20% ) a 96% yield of the benzo-phenone-DMSO adduct [ l,l-diphenyl-2- (methylsulfinyl) ethanol] was isolated at complete reaction (17). 

This interpretation was proved correct by considering the oxidation of a sample of diphenylmethane that had an isotopic purity of 97.0% a,a-dideuterio and 2.7% a-deuterio by mass spectrometry. The oxidation rate observed after the initial 15-second period (see Figure 2), during which the undeuterated and monodeuterated material were destroyed, yielded a second-order rate constant, ki = 0.0148 mole"1 per second. There is thus an appreciable isotope effect ku/kD of about 6 in the ionization of diphenylmethane by potassium ferf-butoxide in DMSO(80%)-tert-butyl alcohol (20% ) at 25°C. This compares with a value of fcH/ D of 9.5 reported for the ionization of triphenylmethane (16). The observation of primary isotope effects of this magnitude requires that the protonation of the diphenylmethide ion by tert-butyl alcohol in DMSO solution does not proceed at the diffusion rate which would, by the principle of microscopic reversibility, require the absence of an isotope effect in the deprotonation step. 

Final confirmation of our interpretation of the rate of oxygen absorption by diphenylmethane was provided by studying the loss of deuterium from the deuterated sample of diphenylmethane. After 1.50 and 2.70 minutes in a solution containing 0.233M potassium ferf-butoxide and 0.10M diarylmethane, and in the absence of oxygen, the recovered diphenylmethane was found to contain dideuterio, monodeuterio, and undeuterated diphenylmethane in the ratios, 74.0 23.8 2.2 (1.5 minutes)... 

Oxidation of Benzhydrol in Basic Solution. Reaction of benzhydrol with oxygen in basic solution results in the formation of benzophenone, or in DMSO solutions the benzophenone—DMSO adduct. Table VIII summarizes data on the oxidation of benzhydrol in three solvents and in the presence of various concentrations of potassium ferf-butoxide. The rates are the maximum oxidation rates, often observed after an inductive period (Figure 3). 

M xanthenol, 0.22M potassium ferf-butoxide in pyridine (80% )—terf-butyl alcohol (20% ) solution at 27° 3°C. b Moles of oxygen/mole of substrate per minute. 

Some of the polymers slowly change their helicity in solution. A chiral crown ether-potassium ferf-butoxide combined system was reported to cause polymerization of methyl, tert-butyl, and benzyl methacrylate to form isotactic polymers that had high rotation values (164). Detailed scrutiny, however, raised questions about the result (135, 165). At first, in the presence of the initiator, the oligomers exhibit considerable activity, but after removal of the catalyst, the optical activity decreases. This decrease may be attributed to unwinding of the helixes in the chain the helicity could be caused by the anchored catalyst. 

Dichlorocarbene cannot be isolated, but it can be produced in the presence of an alkene with which it rapidly reacts. The best dichlorocarbene precursor is the anion C13C , which easily eliminates a chloride ion. This anion is obtained from C13CH and fairly strong bases like potassium ferf-butoxide (KO-ferf-Bu), KOH or NaOH. The deprotonation of C13CH is run very efficiently with a solution of KO-terf-Bu in THF. Alternatively, when a concentrated aqueous solution of NaOH or KOH is vigorously stirred with a chloroform solution of the alkene (which is not miscible with the first) there is only moderate conversion into the corre-... 

Poly(e-mercapto acids). In a series of papers, Overberger and Weise (17, 20, 21) reported the polymerization of e-thiocaprolactone (XXIV) and of some substituted analogs (see Table VI). XXIV could be polymerized in bulk or tetrahydrofuran solution, using bases such as butyllithium, potassium ferf-butoxide, or sodium as initiators. A1C13 as initiator gave a crosslinked product. Linear poly(e-thiocaprolactone) is crystalline and soluble in chlorinated hydrocarbons. 

Setting Up Equip the flask with a stirbar. Working quickly, add 25 mL of a 1 M solution of potassium ferf-butoxide in ferf-butyl alcohol. This reagent is very moisture-sensitive, so exposure to the atmosphere must be minimized. Then add 2.5 mL of 2-bromo-2-methylbutane to the solution and equip the flask for fractional distillation. Complete set-up according to the directions in the Miniscale Procedure of Part A. 

Solutions of potassium ferf-butoxide are highly caustic. Do not allow them to come in contact with your skin. If this should happen, wash the affected area with dilute acetic acid and then copious amounts of water. Wear latex gloves when transferring the solution. 

Why should the exposure of the solution of potassium ferf-butoxide to the atmosphere be minimized ... 

To a solution of potassium ferf-butoxide (0.05 mmol 5 mol%) in tert- mty alcohol (1 mL) in a test tube, a mixture of acetophenone (1 1.0 mmol) and aldehyde (2 1.0 mmol) was added followed by continuous stirring for several minutes at room temperature until the starting materials were completely disappeared (monitored by TLC) thiol (3 1.2 mmol) was then added to the reaction mixture, and was stirred to completion of the reaction. The solvent was evaporated, and chloroform (1 mL) was added and the crude product was subjected to preparative TLC (silica gel, eluent petroleum ether/Et20 = 7 4) to afford a pure p-aryl-p-mercapto ketone 4 in excellent yield (85-95%). The structures of aU the products were established on the basis of physical and spectral properties. 

Is tert-butoxide anion a strong enough base to react significantly with water In other words, can a solution of potassium ferf-butoxide be prepared in water ... 

The potassium should be cut into pieces sufficiently small to pass through the neck of the flask. Sodium in tert.-butyl alcohol can be used, but it is necessary to carry out the subsequent reaction at 125° in sealed tubes. The amount of tert.-butyl alcohol specified is sufficient to provide for complete solution of the potassium as the ferf.-butoxide. 

Distilled ethyl oleate (200 g, 0.65 mole) and absolute alcohol (1.51) are placed in a 5-1 round-bottomed flask under a wide reflux condenser. The alcohol has been previously dried over calcium and is distilled from aluminum ferf-butoxide directly into the reaction flask. Sodium (to a total of 80 g, 3.5 gram-atoms) is added gradually through the reflux condenser at such a rate that vigorous reaction ensues, the flask being occasionally shaken. When the main reaction has ended, more absolute alcohol (200 ml) is added and the mixture is heated on the steam-bath until all the sodium is consumed. Then water (500 ml) is added and the heating continued for a further hour to hydrolyse unchanged ester. The imsaponifiable fraction is extracted with ether. The ether extract is washed with 1 % potassium hydroxide solution and then with water until free from alkali (phenolphthalein) and is dried over sodium sulfate. The ether is distilled off and the residue is fractionally distilled. 49-51 % (84-89 g) of oleyl alcohol are obtained at 150-152°/1 mm. 

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