Potassium Acetate Solution Bicarbonate

A solution of 17-cyanoandrosta-5,16-dien-3jS-ol acetate (46 g) and anhydrous potassium acetate (0.46 g) in methylene dichloride (310 ml) is treated with a mixture of 40% peracetic acid (37 ml) and anhydrous potassium acetate (1.84 g) in methylene dichloride (46 ml), the temperature of the solution being maintained below 25°. The mixture is stored at room temperature for 4 hr and then washed successively with water, 5% sodium bicarbonate solution (aqueous sodium bisulfite, 10g/150g water, has been used to decompose excess reagent before workup) and water until neutral. Evaporation of the dried solution and addition of ether gives 24.1 g of 5oc,6a-epoxy-17-cyanoandrost-16-en-3 -ol acetate mp 187-190°. One recrystallization from methanol gives 20.4 g of oxirane melting at 191-194°. 

Other physical phenomena that may be associated, at least partially, with complex formation are the effect of a salt on the viscosity of aqueous solutions of a sugar and the effect of carbohydrates on the electrical conductivity of aqueous solutions of electrolytes. Measurements have been made of the increase in viscosity of aqueous sucrose solutions caused by the presence of potassium acetate, potassium chloride, potassium oxalate, and the potassium and calcium salt of 5-oxo-2-pyrrolidinecarboxylic acid.81 Potassium acetate has a greater effect than potassium chloride, and calcium ion is more effective than potassium ion. Conductivities of 0.01-0.05 N aqueous solutions of potassium chloride, sodium chloride, potassium sulfate, sodium sulfate, sodium carbonate, potassium bicarbonate, potassium hydroxide, and sodium hydroxide, ammonium hydroxide, and calcium sulfate, in both the presence and absence of sucrose, have been determined by Selix.88 At a sucrose concentration of 15° Brix (15.9 g. of sucrose/100 ml. of solution), an increase of 1° Brix in sucrose causes a 4% decrease in conductivity. Landt and Bodea88 studied dilute aqueous solutions of potassium chloride, sodium chloride, barium chloride, and tetra-... 

A solution in 500 c.cs. water is made from 110 gms. potassium acetate, 26 gms. potassium carbonate and 28 gms. potassium bicarbonate, and poured into a lead cell or glass beaker, which need contain no anode chamber. The beaker should be placed in a basin of cold water, and the cathode should take the form of a thin lead pipe, with a copper connection soldered to it, wound in the form of a coil, and placed close to the inner walls of the beaker. Through this pipe a supply of cold water is run, so that the temperature is maintained at 25°—30° during the electrolysis. The anode is of platinum, and should be so arranged that it can be rotated. The current density is 20—25 amperes per sq. dcm., and the E.M.F. 7—8 volts. 

Aminopenicillanic acid (2.16 g) is dissolved in 20 ml of a one molar aqueous solution of potassium bicarbonate and 10 ml of acetone. The resultant solution is cooled in an ice-water bath and to it is added with stirring a solution of 2.7 g of alpha-methoxy-3,4-dichloro-phenylacetyl chloride in 10 ml of acetone. The pH is adjusted to 7-8 and upon completion of the addition the reaction medium is stirred for 15 min at ice bath temperature and then for 2.5 h at room temperature, maintaining the pH range between 7 and 8. The solution is extracted once with ether and then adjusted to pH 2.5 with 20% phosphoric acid. The acidic solution is extracted once with 30 ml of butyl acetate and again with 10 ml of butyl acetate. These combined butyl acetate extracts are thereafter successively washed twice with water and reextracted at pH 7 with 0.5 N aqueous potassium hydroxide solution. The aqueous layer is washed twice with ether and the remaining organic solvent is then removed by evaporation under reduced pressure. The washed aqueous layer is then lyophilized and the residue thus obtained taken up in acetone. The crystal line product is collected by filtration and dried to yield the potassium salt of 6-(a-methoxy-3,4-dichlorophenylacetamido)penicillanic acid. Upon treatment with mineral acid of an aqueous solution of the compound so prepared, there is obtained the free acid, 6-(a-methoxy-3,4-dichlorophenylacetamido)penicillanic acid. 

A mixture of 200 g. (3.45 moles) of propionaldehyde and 200 g. of ether is cooled to 0° in a flask equipped with a condenser, a dropping funnel, a thermometer, and a stirrer. Ten milliliters of a 15% aqueous solution of potassium hydroxide is added with vigorous stirring. The reaction mixture is cooled so that the temperature does not rise above 10-12°. When the mixture has cooled to about 6-8° another portion of potassium hydroxide solution is introduced in the same manner as before. Base is added in this way until there is no longer an evolution of heat upon addition. This requires 70-80 ml. of base solution and 35-40 minutes. The aqueous layer is separated and washed with ether. The combined ethereal solutions are washed with dilute aqueous acetic acid and with dilute sodium bicarbonate solution and then dried over anhydrous sodium sulfate. The ether is distilled off on a water bath, and the residue is distilled through a 25-cm. Vigreux column. At a pressure of 80-l(K) mm., there is first obtained a mixture of unreacted propionaldehyde and 2-methyl-2-pentenal. The propionaldol is collected at 84-86°/ll mm., and the yield is around 55-60%. 

From the absorption spectra of the various green solutions produced by the reaction of hydrogen peroxide on a cobaltous salt in the presence of potassium (or sodium) bicarbonate, acetate, tartrate, citrate or oxalate, Durrant - concluded that the green color depended on complex ions with the >Co O Co < nucleus, and that the differences in tint of green and in absorption spectra depended probably on the various association of carbonyl groups attached to the nucleus. On account of his detailed study, the reaction discovered by Field has been called Field-Durrant reaction ... 

A concentrated solution of monochloroacetic acid is neutralised with sodium bicarbonate, and then heated with potassium cyanide, whereby sodium cyano-acetate is obtained ... 

Benzenetetrol. 1,2,3,5-Tetrahydroxybenzene (64) forms needles (mp 165°C) from water. The compound is easily soluble ia water, alcohol, and ethyl acetate and is iasoluble ia chloroform and benzene. In aqueous potassium bicarbonate solution sparged with carbon dioxide,... 

The crude ketal from the Birch reduction is dissolved in a mixture of 700 ml ethyl acetate, 1260 ml absolute ethanol and 31.5 ml water. To this solution is added 198 ml of 0.01 Mp-toluenesulfonic acid in absolute ethanol. (Methanol cannot be substituted for the ethanol nor can denatured ethanol containing methanol be used. In the presence of methanol, the diethyl ketal forms the mixed methyl ethyl ketal at C-17 and this mixed ketal hydrolyzes at a much slower rate than does the diethyl ketal.) The mixture is stirred at room temperature under nitrogen for 10 min and 56 ml of 10% potassium bicarbonate solution is added to neutralize the toluenesulfonic acid. The organic solvents are removed in a rotary vacuum evaporator and water is added as the organic solvents distill. When all of the organic solvents have been distilled, the granular precipitate of 1,4-dihydroestrone 3- methyl ether is collected on a filter and washed well with cold water. The solid is sucked dry and is dissolved in 800 ml of methyl ethyl ketone. To this solution is added 1600 ml of 1 1 methanol-water mixture and the resulting mixture is cooled in an ice bath for 1 hr. The solid is collected, rinsed with cold methanol-water (1 1), air-dried, and finally dried in a vacuum oven at 60° yield, 71.5 g (81 % based on estrone methyl ether actually carried into the Birch reduction as the ketal) mp 139-141°, reported mp 141-141.5°. The material has an enol ether assay of 99%, a residual aromatics content of 0.6% and a 19-norandrost-5(10)-ene-3,17-dione content of 0.5% (from hydrolysis of the 3-enol ether). It contains less than 0.1 % of 17-ol and only a trace of ketal formed by addition of ethanol to the 3-enol ether. 

To the epoxide dissolved in a minimal amount of chloroform or ether is added a corresponding solution of freshly prepared thiocyanic acid (20 fold excess) as described above (acetic acid has also been used as solvent). The resulting solution is allowed to stand at least 70 hr at room temperature. (Some workers have protected the reaction mixture from light during this period). The reaction mixture is worked up by washing first with a 10% solution of sodium carbonate, sodium bicarbonate or potassium bicarbonate, and then water. The remaining ether extract is dried (Na2S04) and evaporated under vacuum. The crude thiocyanatohydrin is crystallized from an appropriate solvent or treated with methanesulfonyl chloride s (see below). 

Preparation of 3a-Hydroxy-5) -pregn-17(20)-en-21-oic Acid . A solution of 15 g of 3a-acetoxy-5jS-pregnan-20-one in 290 ml of glacial acetic acid is treated with 13 g of bromine at room temperature. After complete addition of bromine the reaction mixture is heated at 40-50° for 30 min, and the product precipitated with water and filtered. The product is taken up in ethyl acetate (500-600 ml) and the resulting solution washed with dilute aqueous potassium bicarbonate. The solvent is concentrated in vacuo and the product crystallized from acetone to give 16g of dibromide mp, 173-175°. 

A solution of the bromo ketone (1 g) and sodium iodide (1 g) in 40 ml of acetone is refluxed for 20 min. The hot solution is filtered and the filtrate added to a mixture of 5 g of potassium bicarbonate and 4 ml of acetic acid. This mixture is then refluxed overnight, cooled and poured into a large excess of water. The resulting white precipitate is collected by filtration, dried in vacuo and finally recrystallized twice from methanol to afford 0.49 g of 3, 21-diacetoxypregna-5,16-dien-20-one mp 153-155° [a]jj —40° (CHCI3). 

Hydroxy-B-homo-5a-cholestan-7-one acetate (54b) A solution of 3/3-hydroxy-5a-cholestan-7-one acetate (51b 5 g mp 146-148°) in dioxane-ethanol (100 ml, 1 1) is placed in a 250 ml three-necked flask equipped with a mechanical stirrer and thermometer and is cooled to 0° (iee-salt bath). Powdered potassium cyanide (7.3 g) is added portionwise with stirring. Acetic acid (8 ml) is then added dropwise with constant stirring over 30 min. The resultant mixture is stirred for 1 hr at 0° C and for an additional 2 hr at room temperature. It is then poured into ice water (200 g ice, 100 ml water) and after standing for 1 hr the precipitate is collected by filtration. The product is dissolved in ether (100 ml), the ether solution is washed with 5% sodium bicarbonate, water and dried over anhydrous sodium sulfate. The filtrate is evaporated at reduced pressure and the solid residue (5.1 g) is crystallized from ethyl acetate (30 ml) to yield 2.8 g of cyanohydrin (52b) mp 160-164° repeated crystallization from the same solvent gives a product mp 164-167°. An alternative method of isolation of the cyanohydrin is used when 100 g or larger quantities are worked up. The reaction mixture is poured directly into a mixture of ice water and sodium bicarbonate, the precipitate (mp 155-156°) is washed well with water, dried and used directly for the next step. 

The crude diol (47)(3.8 g) is dissolved in 160 ml of methanol, mixed with 4 g of potassium hydroxide in 10 ml of water and 20 ml of methanol, and warmed under nitrogen for 5 min. Acetic acid (4 ml) is added and the solution is poured into an aqueous solution of sodium chloride. The product is extracted 3 times with ethyl acetate and the extracts are washed with 10% sodium bicarbonate and then with water. The solvent is removed by distillation and the residue is recrystallized from acetone-petroleum ether to give 1.85 g of (48) mp 275-277°. 

Into a suspension of 8 g of sodium acetate m 400 mL of a solution of 1 part acetic acid and 10 parts fluorotnchloromethane is passed at -75 C a stream of fluonne diluted to 10% with nitrogen The reacuon is stirred with a Vibromixer A solution of 4-methylacetanilide (20 mmol) in a mixture of dichloromethane and fluorotnchloromethane cooled to -75 °C i s added to 20 mmol of acetyl hypofluonte as determined by titration with potassium iodide After 5 min the mixture is poured into water, and the orgamc layer is washed with sodium bicarbonate soluaon and dried over anhydrous magnesium sulfate After concentrauon and column chromatography over silica gel and elution with chloroform, 2-fluoro-4-methylacetanilide IS obtained m 85% yield... 

Chloro-1 -methyl-6-phenyl4H-s-triazolo-[4,3-a] [1,4] -benzodiazepine A stirred suspension of 5-chloro-2-[3-(bromomethyl)-5-methyl4H-1,2,4-triazol4-yl] -benzophenone (391 mg, 0.001 mol) in tetrahydrofuran (15 ml) was cooled in an ice-bat hand treated with a saturated solution of ammonia in methanol (12.5 ml). The resulting solution was allowed to warm to ambient temperature and stand for 24 hours. It was then concentrated in vacuo. The residue was suspended in water, treated with a little sodium bicarbonate and extracted with methylene chloride. The extract was washed with brine, dried with anhydrous potassium carbonate and concentrated. The residue was crystallized from methylene chloride-ethyl acetate to give... 

A solution of 88.5 parts of L-phenylalanine methyl ester hydrochloride in 100 parts of water is neutralized by the addition of dilute aqueous potassium bicarbonate, then is extracted with approximately 900 parts of ethyl acetate. The resulting organic solution is washed with water and dried over anhydrous magnesium sulfate. To that solution is then added 200 parts of N-benzyloxycarbonyl-L-aspartic acid-a-p-nitrophenyl, -benzyl diester, and that reaction mixture is kept at room temperature for about 24 hours, then at approximately 65°C for about 24 hours. The reaction mixture is cooled to room temperature, diluted with approximately 390 parts of cyclohexane, then cooled to approximately -18°C in order to complete crystallization. The resulting crystalline product is isolated by filtration and dried to afford -benzyl N-benzyloxycarbonvI-L-aspartyl-L-phenylalanine methyl ester, melting at about 118.5°-119.5°C. 

To a solution of 6.36 parts of 17(3-hydroxy-17a-methyl-5o -androst-Ten-3-one in 95 parts of acetic acid and 12 parts of water is added 40 parts of lead tetracetate and 0.6 part of osmium tetroxide. This mixture is stored at room temperature for about 24 hours, then is treated with 2 parts of lead tetracetate. Evaporation to dryness at reduced pressure affords a residue, which is extracted with benzene. The benzene extract is washed with water, and extracted with aqueous potassium bicarbonate. The aqueous extract is washed with ether, acidified with dilute sulfuric acid, then extracted with ethyl acetate-benzene. This organic extract is washed with water, dried over anhydrous sodium sulfate, and concentrated to dryness in vacuo. To a solution of the residual crude product in 20 parts of pyridine is added 10 parts of 20% aqueous sodium bisulfite and the mixture is stirred for about 20 minutes at room temperature. 

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