Potassium hydroxide equipment

Ammonia is conveniently obtained from a cylinder of the Uquefled gas the cylinder must be equipped with a reducing valve. The rate of flow of the gas may be determined by passage through a bubble counter containing a small volume of concentrated potassium hydroxide solution (12 g. of KOH in 12 ml. of water). A safety bottle should be inserted between the cylinder and the reaction vessel. 

Potassium Phosphates. Potassium phosphate salts are analogous to the sodium salts and share many of the same functional properties. The higher cost of potassium hydroxide has restricted these salts to appHcations where high solubiUty or nutrient value is important. Potassium salts are manufactured like their sodium analogues, often on the same equipment. Many of the potassium phosphates are more deflquescent than their sodium analogues and may require special storage and moistureproof containers. 

Potassium forms corrosive potassium hydroxide and Hberates explosive hydrogen gas upon reaction with water and moisture. Airborne potassium dusts or potassium combustion products attack mucous membranes and skin causing bums and skin cauterization. Inhalation and skin contact must be avoided. Safety goggles, full face shields, respirators, leather gloves, fire-resistant clothing, and a leather apron are considered minimum safety equipment. 

A 600-mL, three-necked, round-bottomed flask 1s equipped with a mechanical stirrer, a short gas inlet tube, and an efficient reflux condenser fitted with a potassium hydroxide drying tube. The flask is charged with 13.4 g (0.05 mol) of 3-ben2y1-5-(2-hydroxyethyl)-4-methyl-l,3-th1azol1um chloride (Note 11, 72.1 g (1.0 mol) of butyraldehyde (Note 2). 30.3 g (0.3 mol) of triethylamine (Note 2), and 300 raL of absolute ethanol. A slow stream of nitrogen (Note 3) is begun, and the mixture is stirred and heated In an oil bath at 80°C. After 1.5 hr the reaction mixture is cooled to room temperature and concentrated by rotary evaporation. The residual yellow liquid Is poured Into 500 mL of water contained 1n a separatory funnel, and the flask is rinsed with 150 mL of dichloromethane which is then used to extract the aqueous mixture. The aqueous layer is extracted with a second 150-mL portion of... 

Cyalohexylideneaaetonit ri-le. A 1-L three-necked, round-bottomed flask equipped with a reflux condenser, mechanical stirrer and addition funnel, is charged with potassium hydroxide (855 pellets, 33.0 g, 0.5 mol. Note 1) and acetonitrile (250 ml. Notes 2 and 3). The mixture is brought to reflux and a solution of cyclohexanone (49 g, 0.5 mol. Note 4) in acetonitrile (100 mL) is added over a period of 0.5-1.0 hr. Heating at reflux is continued for 2 hr (Note 5) after the addition is complete and the hot solution is then poured onto cracked ice (600 gl. The resulting binary mixture is separated... 

Commerioal ether was stored over potassium hydroxide pellets and used without being distilled. Because some heat is evolved when the ether is added to the alumina, the fiask is equipped with a condenser. 

The amine, under the name N,N,N, N -tetramethyl-methylenediamine, may be purchased from Ames Laboratories, South Norwalk, Connecticut. The checkers prepared it by the following procedure. A solution of 60.7 g. (0.75 mole) of 37% aqueous formaldehyde solution is placed in an 800-ml. beaker equipped with a mechanical stirrer and thermometer, and cooled in an ice bath. Two hundred seventy-one grams (1.50 moles) of a 25% aqueous solution of dimethylamine is added to this solution at a rate such that the reaction temperature is kept below 15°. The solution is stirred for 30 minutes after the addition is complete, and potassium hydroxide pellets (approximately 150 g.) are added in portions until the reaction mixture separates into two layers. The upper layer is separated, dried over potassium hydroxide pellets overnight, and distilled to give 59 -64 g. (77-83%) of bis(dimcthylamin())mclliane, b.p. 83 84°. ... 

B. 3-Hydroxycinchoninic acid. A 3-1., four-necked flask (Note 1) is equipped with a sealed mechanical stirrer, gas inlet tube, gas outlet consisting of a 1-mm. capillary (Note 7), and thermometer. The flask is charged with a freshly prepared solution containing 448 g. (8 moles) of reagent grade (85% minimum assay) potassium hydroxide and 900 ml. of water. The solution (hot from dissolution of potassium hydroxide) is stirred and 147 g. (1 mole) of isatin (Note 8) is introduced. The solid quickly dissolves to give an orange-yellow solution. 

This material was made up with distilled water to provide 41 g per liter, and the mixture was adjusted to pH 7.0 with potassium hydroxide solution. To the mixture were added per liter 5.0 g of calcium carbonate and 7.5 ml of soybean oil. 2,000 ml portions of this medium were then added to fermentation vessels, equipped with stirrers and aeration spargers, and sterilized at 121°C for 60 minutes. After cooling the flasks were inoculated with a suspension of strain No. ATCC 11924 of Streptomyces lavendulae, obtained from the surface of agar slants. The flasks were stirred for 4 days at 28°C at approximately 1,700 rpm. At the end of this period the broth was found to contain cycloserine in the amount of about 250 C.D.U./ml of broth. The mycelium was separated from the broth by filtration. The broth had a pH of about 7.5. Tests showed it to be highly active against a variety of microorganisms. 

Initially, 4.5 g (0.08 mol) pulverized potassium hydroxide was dissolved in 300 ml isopropanol in a 500 ml four-neck flask equipped with stirrer, intensive cooler, dropping funnel and feed pipe for the gas treatment with nitrogen. 

Sodium hydroxide (NaOH) and potassium hydroxide (KOH) solutions do not dissolve tantalum, but tend to destroy the metal by formation of successive layers of surface scale. The rate of the destruction increases with concentration and temperature. Damage to tantalum equipment has been experienced unexpectedly when strong alkaline solutions are used during cleaning and maintenance. 

A 250-mL, three-necked, round-bottomed flask equipped with stirrer and distillation head suitable for vacuum distillation is filled with 120 g of freshly distilled 2-pyrrolidone. The reaction mass is heated under nitrogen to 80° C. Flake potassium hydroxide (3.4 g) is then added. The water formed is rapidly distilled from the flask under 1 mbar pressure. The hot solution is then rapidly... 

C. 4-Amino-l-tert-butyloxycarbonylpiperidine-4-carboxylic acid (3). A 2000-mL, round-bottomed flask equipped with a magnetic stirbar is charged with a suspension of the hydantoin 2 (40.0 g, 0.8 mol) in 340 mL of THF (Note 12), and 340 mL of 2.0M potassium hydroxide solution (Note 13) is added in one portion. The flask is stoppered and the reaction mixture is stirred for 4 hr (Note 14) and then poured into a 1000-mL separatory funnel. The layers are allowed to separate over 45 min and the aqueous layer is then drained into a 1000-mL round-bottomed flask. This solution is cooled at 0°C while the pH is adjusted to 8.0 by the slow addition of ca. 100 mL of 6.0N HC1 solution. The resulting solution is further acidified to pH 6.5 by slow addition of 2.0 N HC1 solution (Note 15). The white precipitate which appears is collected by filtration on a Buchner funnel and the filtrate is concentrated to a volume of 60 mL to furnish additional precipitate which is collected by filtration. The combined portions of white solid are dried at room temperature under reduced pressure (65°C 0.5 mm) for 12 hr and then suspended in 100 mL of chloroform (Note 16) and stirred for 45 min. The white solid is filtered and then dried under reduced pressure (85°C 0.5 mm) for 24 hr to yield 13.4-14.1 g (64-68%) (Note 17) of the amino acid 3 as a white solid (Note 18). 

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