Sodium bicarbonate solution preparation

Fluorescamine stain 0.25 mg/ml fluorescamine (Sigma) in sodium bicarbonate solution (prepare fresh daily)... 

Standard working solutions 0, 8, 16,24, 32,40 mM sodium bicarbonate solutions prepared by dilution from 1000 mM stock solution. ... 

In a 1500 ml. round-bottomed flask, carrying a reflux condenser, place 100 g. of pure cydohexanol, 250 ml. of concentrated hydrochloric acid and 80 g. of anhydrous calcium chloride heat the mixture on a boiling water bath for 10 hours with occasional shaking (1). Some hydrogen chloride is evolved, consequently the preparation should be conducted in the fume cupboard. Separate the upper layer from the cold reaction product, wash it successively with saturated salt solution, saturated sodium bicarbonate solution, saturated salt solution, and dry the crude cycZohexyl chloride with excess of anhydrous calcium chloride for at least 24 hours. Distil from a 150 ml. Claisen flask with fractionating side arm, and collect the pure product at 141-5-142-5°. The yield is 90 g. 

In a 250 ml. separatory funnel place 25 g. of anhydrous feri.-butyl alcohol (b.p. 82-83°, m.p. 25°) (1) and 85 ml. of concentrated hydrochloric acid (2) and shake the mixture from time to time during 20 minutes. After each shaking, loosen the stopper to relieve any internal pressure. Allow the mixture to stand for a few minutes until the layers have separated sharply draw off and discard the lower acid layer. Wash the halide with 20 ml. of 5 per cent, sodium bicarbonate solution and then with 20 ml. of water. Dry the preparation with 5 g. of anhydrous calcium chloride or anhydrous calcium, sulphate. Decant the dried liquid through a funnel supporting a fluted Alter paper or a small plug of cotton wool into a 100 ml. distilling flask, add 2-3 chips of porous porcelain, and distil. Collect the fraction boiling at 49-51°. The yield of feri.-butyl chloride is 28 g. 

The method is generally applicable when other modes of esterification are either slow, inefficient, or likely to cause isomerisation it is, however, time-consuming and expensive. Small quantities of acid impurities are sometimes produced, hence it is advisable to wash the ester with saturated sodium bicarbonate solution. The silver salt can usually be prepared by dissolving the acid in the calculated quantity of standard ammonium hydroxide solution and... 

This product is sufficiently pure for the preparation of phenylacetic acid and its ethyl ester, but it contains some benzyl tso-cyanide and usually develops an appreciable colour on standing. The following procedure removes the iso-cyanide and gives a stable water-white compound. Shake the once-distilled benzyl cyanide vigorously for 5 minutes with an equal volume of warm (60°) 60 per cent, sulphuric acid (prepared by adding 55 ml. of concentrated sulphuric acid to 100 ml. of water). Separate the benzyl cyanide, wash it with an equal volume of sa+urated sodium bicarbonate solution and then with an equal volume of half-saturated sodium chloride solution- Dry with anhydrous magnesium sulphate and distil under reduced pressure. The loss in washing is very small (compare n-Butyl Cyanide, Section 111,113, in which concentrated hydrochloric acid is employed). 

Propiophenone. Prepare a solution of diphenyl-cadmium in 110 ml. of dry benzene using 4 9 g. of magnesium, 32 4 g. of bromobenzene and 19 5 g. of anhydrous cadmium chloride. Cool the solution to 10°, and add during 3 minutes a solution of 14 -8 g. of propionyl chloride (b.p. 78-79°) in 30 ml. of dry benzene use external coohng with an ice bath to prevent the temperature from rising above 40°. Stir the mixture for 2 hours at 25-35°. Work up the product as detailed above except that 6 per cent, sodium carbonate solution should replace the saturated sodium bicarbonate solution. The yield of propiophenone, b.p. 100-102°/16 mm., is 17 6 g. 

The purified commercial di-n-butyl d-tartrate, m.p. 22°, may be used. It may be prepared by using the procedure described under i o-propyl lactate (Section 111,102). Place a mixture of 75 g. of d-tartaric acid, 10 g. of Zeo-Karb 225/H, 110 g. (136 ml.) of redistilled n-butyl alcohol and 150 ml. of sodium-dried benzene in a 1-litre three-necked flask equipped with a mercury-sealed stirrer, a double surface condenser and an automatic water separator (see Fig. Ill, 126,1). Reflux the mixture with stirring for 10 hours about 21 ml. of water collect in the water separator. FUter off the ion-exchange resin at the pump and wash it with two 30-40 ml. portions of hot benzene. Wash the combined filtrate and washings with two 75 ml. portions of saturated sodium bicarbonate solution, followed by lOu ml. of water, and dry over anhydrous magnesium sulphate. Remove the benzene by distillation under reduced pressure (water pump) and finally distil the residue. Collect the di-n-butyl d-tartrate at 150°/1 5 mm. The yield is 90 g. 

The mauve colored cobalt(II) carbonate [7542-09-8] of commerce is a basic material of indeterminate stoichiometry, (CoCO ) ( (0 )2) H20, that contains 45—47% cobalt. It is prepared by adding a hot solution of cobalt salts to a hot sodium carbonate or sodium bicarbonate solution. Precipitation from cold solutions gives a light blue unstable product. Dissolution of cobalt metal in ammonium carbonate solution followed by thermal decomposition of the solution gives a relatively dense carbonate. Basic cobalt carbonate is virtually insoluble in water, but dissolves in acids and ammonia solutions. It is used in the preparation of pigments and as a starting material in the preparation of cobalt compounds. 

D. a-Allyl- -bromoelhyl ethyl ether. The same apparatus is used as in the preparation of allylmagnesium bromide. The flask is charged with an amount of the Grignard solution (part C) equivalent to 2.78 moles of allylmagnesium bromide (or chloride) and cooled in an ice bath. A solution of 580 g. (2.5 moles) of o , 3-dibromoethyl ethyl ether (part B) in an equal volume of anhydrous ether is added slowly with stirring over a period of 3-4 hours. The mixture is allowed to stand overnight and is then hydrolyzed with 75 ml. of 20% acetic acid followed by 500 ml. of water. The ether layer is separated, washed with four 100-ml. portions of 10% aqueous sodium bicarbonate solution followed by four 100-ml. portions of saturated aqueous sodium chloride solution, dried over 100 g. of anhydrous calcimn sulfate, and distilled under reduced pressure. The yield of colorless a-allyl-/3-bromoethyl ethyl ether is 370-396 g. (77-82% based on the a, 3-dibromoethyl ethyl ether), b.p. 72-75°/21 mm., 1.4600-1.4606. 

A-Homo-cholest-4a-en-3-one (16a) A total of 200 ml of a cold 0.232 M solution of diazomethane in methylene dichloride is added dropwise to a stirred solution of cholestenone (15a 5.6 g) in anhydrous methylene dichloride (25 ml) containing freshly prepared fiuoroboric acid catalyst. Nitrogen evolution begins immediately, and after 5 min the colorless solution turns cloudy due to precipitated polymethylene. After the addition is complete, the mixture is stirred for 1 hr and filtered. The filtrate is diluted with ether, washed with saturated sodium bicarbonate solution followed by... 

A perbenzoic acid solution in benzene is prepared as in Chapter 17, Section II. (This solution is approximately 1.8 A/ in perbenzoic acid.) To 67 ml (approx. 0.12 mole of perbenzoic acid) of this solution contained in an Erlenmeyer flask is added 0.10 mole of the ketone in one batch. The resulting solution is swirled at intervals and allowed to stand at room temperature for 10 days. The solution is then washed three times with 50-ml portions of saturated sodium bicarbonate solution to remove benzoic acid and unreacted peracid, and is then washed with water. The solution is dried (anhydrous sodium sulfate), the benzene is evaporated, and the residue is fractionally distilled at reduced pressure to give the ester. 

The oxidizing agent is prepared in a 500-ml flask equipped with a magnetic stirrer and cooled in an ice bath as follows In the flask are placed 60 ml of concentrated sulfuric acid and 20 ml of water, and the solution is cooled to 10°. Potassium persulfate (42 g, 0.15 mole) is added slowly to the stirred solution while maintaining the temperature below 10°. The solution is diluted with an additional 65 ml of water maintaining the temperature below 15°. The solution is now cooled to about 7° and 0.08 mole of the ketone is added over 40 minutes. After the addition has been completed, the solution is allowed to come to room temperature and stirring is continued for 20 hours. The solution is diluted carefully with 150 ml of water and extracted twice with 75-ml portions of ether. The ether is washed with sodium bicarbonate solution, followed by water, and the ethereal solution is dried. Removal of the solvent, followed by fractional distillation, affords the product ester. 

The starting material for the above step may be prepared as follows 5 g (0.016 mol) of N -(p-methoxyphenyl)-p-chlorobenzhydrazide hydrochloride and 4.75 g (0.018 mol) of benzyl levulinoyloxyacetate were heated In 25 ml of glacial acetic acid for 3 hours at 80°C. The solvent was then evaporated off under vacuum. The residue was taken up in chloroform and the solution was washed neutral by shaking with sodium bicarbonate solution and thereafter with water. After drying the chloroform solution, this was subjected to chromatography on aluminium oxide, the eluate was concentrated by evaporation and the viscous oil remaining as residue was crystallized by adding ether. The compound melted at 94°-95 t. The yield was 4.1 g which corresponds to 50.7% of the theoretical yield. 

A mixture of B g (0.0356 mol) of p-(2.2-dichlorocyclopropyl)phenol, 11.2 g (0.2B mol) of sodium hydroxide pellets, 11 g of chloroform and 350 ml of acetone was prepared at 0°C. The cooling bath was removed, the mixture stirred for a minute and then heated on a steam bath to reflux temperature. The reaction mixture was stirred at reflux for three hours and then concentrated in vacuo. The residual gum was partitioned between dilute hydrochloric acid and ether, and the ether layer was separated, dried and concentrated in vacuo. The residual oil (14 g) was partitioned between dilute aqueous sodium bicarbonate and ether. The sodium bicarbonate solution was acidified with concentrated hydrochloric acid and extracted with ether. The ether solution was dried over anhydrous sodium sulfate and concentrated. The residue (9.5 g of yellow oil) was crystallized twice from hexane to give 6.0 g of 2-[p-(2,2-dlchlorocyclopropyDphenoxyl -2-methyl propionic acid in theformof apalecream[Pg.347]

Step A Preparation of (2 -isopropylidenedioxy)-propyl o-nitrobenzoate-SSS g of 2 -di-methyl4-hydroxymethyl-1 -dloxolane were dissolved under agitation In 60 cc of anhydrous pyridine. The solution was cooled to i-5 G and 86.5 g of o-nitrobenzoyl chloride (prepared by Leckermann et a., 8er. vol. 80,p.488,1947) were slowly introduced Into it. The reaction mixture was agitated for a period of two hours at room temperature and then was poured into 500 cc of ether. The mixture was filtered and the filtrate was washed successively with 0.5 N sulfuric acid solution, with aqueous sodium bicarbonate solution and finally with water until the wash waters were neutral. The washed solution was dried over sodium sulfate and filtered again. The filtrate was distilled to dryness under vacuum to obtain 116.5 g (being a yield of 92%) of (2,3-isopropylidenedioxy)-propyl o-nitrobenzoate in the form of a yellow oil which distilled at 178 to 180°C at a pressure of 1 mm. 

Preparation of 2-Bromo-3-Hexyne A solution of 13B g of 3-hexyne-2-ol and 9 g of pyridine in 13B ml of anhydrous ether was treated with 175 g of phosphorus tribromide, added dropwise over a period of about 20 minutes at a temperature of about -10°C. The reaction mixture was permitted to come to room temperature while stirring for about 3 hours, and was then heated to refluxing for about 1 hour. After cooling, the reaction mixture was poured over about 50 g of crushed ice. A two-phase system formed, and the ether layer was separated, washed with dilute sodium bicarbonate solution, dried over anhydrous potassium carbonate and fractionally distilled. The 2-bromo-3-hexyne formed in the reaction was collected at 75°C at the pressure of 50 mm of mercury. 

The combined ether extracts were washed with 5% aqueous sodium bicarbonate solution, dried over anhydrous sodium sulfate, and fractionally distilled in vacuo. The fraction boiling at about 145° to 150°C at the pressure of 0.5 mm of mercury, weighing 61 g and consisting of 1-methyl-5-allyl-5-(1-methyl-2-pentynyl) barbituric acid, was collected. The only distillate was substantially pure, and could be used as such In pharmaceutical preparation or a salt could be prepared therefrom according to the procedures disclosed hereinafter. On standing, the oil crystallized. The crystalline 1-methyl-5-allyl-5-( 1-methyl-2-pentynyl) barbituric acid melted at about 60° to 64°C after recrystallization from dilute ethanol. 

Preparation of 3-(N-Formyl-N-Methyl)-Aminopropyl Chloride 50 grams of 3-(N-formyl-N-methyl)-aminopropanol-1 obtained above is dissolved in a mixture of 100 ml of chloroform and 25 grams of pyridine. 40 grams of thionyl chloride is then slowly added while maintaining the temperature below 65°C. After 6 hours of refluxing, the mixture is washed with water, then with sodium bicarbonate solution and again with water and then dried over magnesium sulfate and the solvent distilled off in vacuo. Fractional distillation at 1 mm pressure yields substantially pure 3-(N-formyl-N-methyl)-aminopropyl chloride. 

In preparing ethers of phenols, aqueous IN sodium hydroxide should be substituted for the sodium bicarbonate solution. 

Mixtures of 25-30% fluorine diluted with nitrogen were used in this work. The gas mixtures were prepared in a secondary container. The appropriate polyether was dissolved either in perfluoro-2-butyl-THF (FC-75) or in Krytox GPL 100 (a fluorinated oil), which also contained about 5 g of pulverized NaF to absorb the relased HE The reaction mixture was cooled to - 10°C, stirred with the aid of a vibromixer and irradiated with a 450-W medium-pressure mercury lamp. A stream of fluorine in nitrogen (ca. 140 ml/min) was passed into the mixture such that the temperature did not rise above +10°C. The reaction was stopped after 200 mmol of fluorine had been passed through. The mixture was poured into water and the organic layer was washed with sodium bicarbonate solution. The water layer was extracted twice with CFCL. The combined fluorocarbon fractions were washed with water, dried with MgS04, and filtered, and the solvent was removed under reduced pressure. 

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