Sodium carbonate, solution preparation

All hydrocarbons prepared by th -. Wurtz reaction contain small quantities of unsaturated hydrocarbons. These may be removed by shaking repeatedly with 10 pier cent, of the volume of concentrated sulphuric acid until the acid is no longer coloured (or is at most extremely pale yellow) each shaking should be of about 5 minutes duration. The hydrocarbon is washed with water, 10 pier cent sodium carbonate solution, water (twice), and dried with anhydrous magnesium or calcium sulphate. It is then distilled from sodium two distillations are usually necessary... 

P Keto esters (t.g., ethyl ocetoacetate) are soluble in solutions of caustic alkalis but not in sodium carbonate solution. They give colours with freshly prepared ferric chloride solution a little alcohol should be added to bring the ester into solution. Sodium ethoxide solution reacts to yield sodio compounds, which usually crystallise out in the cold. Phenylhydrazine yields pyrazolones. They are hydrolysed by boiling sulphuric acid to the Corresponding ketones, which can be identified as usual (Section 111,74). 

Methyl p-toluenesulphonate. This, and other alkyl esters, may be prepared in a somewhat similar manner to the n-butyl ester with good results. Use 500 g. (632 ml.) of methyl alcohol contained in a 1 litre three-necked or bolt-head flask. Add 500 g. of powdered pure p-toluene-sulphonyl chloride with mechanical stirring. Add from a separatory funnel 420 g. of 25 per cent, sodium hydroxide solution drop by drop maintain the temperature of the mixture at 23-27°. When all the alkali has been introduced, test the mixture with litmus if it is not alkaline, add more alkali until the mixture is neutral. Allow to stand for several hours the lower layer is the eater and the upper one consists of alcohol. Separate the ester, wash it with water, then with 4 per cent, sodium carbonate solution and finally with water. Dry over a little anhydrous magnesium sulphate, and distil under reduced pressure. Collect the methyl p-toluenesulphonate at 161°/10 mm. this solidifies on cooling and melts at 28°. The yield is 440 g. 

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. 

According to the literature, the product obtained in this manner may contain ethyl adipate. To remove this, the product is cooled to 0° and run slowly into 600 cc. of 10 per cent potassium hydroxide solution maintained at 0° with ice-salt. Water is added until the salt which separates has dissolved, and the cold alkaline solution is extracted twice with 200-cc. portions of ether. The alkaline solution, kept at 0°, is run slowly into 900 cc. of 10 per cent acetic acid solution with stirring, the temperature remaining below 1° (ice-salt). The oil which separates is taken up in 400 cc. of ether, and the aqueous solution is extracted with four 250-cc. portions of ether. The ether extract is washed twice with cold 7 per cent sodium carbonate solution and dried over sodium sulfate. After removal of the ether the residue is distilled, b.p. 7g-8i°/3 mm. The recovery is only 80-85 per cent, and in a well-conducted preparation the ethyl adipate eliminated amounts to less than one per cent of the total product. Unless the preparation has proceeded poorly the tedious purification ordinarily is best omitted. 

Acetylene and Potassium in Liquid Ammonia Potassium (40 g) is dissolved in 1 liter of dry liquid ammonia. Dry acetylene is then bubbled into the solution until the blue color is discharged. A solution of 15 g of estrone in 300 ml of dioxane is prepared and diluted with 300 ml of ether, cooled, and added to the potassium acetylide solution over a period of 10 min. The liquid ammonia is allowed to evaporate, an additional 500 ml of ether is added, and the mixture is allowed to stand overnight. About 3 liters of 5 % sulfuric acid is added and the organic layer separated. The water layer is re-extracted with fresh ether, and the combined ether extracts are washed twice with 5 % sodium carbonate solution, th6n several times with water, and finally evaporated under reduced pressure. The residue is dissolved in 150 ml of methanol, then an equal quantity of hot water is added and the mixture cooled. The precipitated solid is collected, washed with cold 60 % methanol and crystallized once from methanol-water to give 14.8 g (85%) of 17a-ethynylestradiol mp 143-144°. 

The 0 -(p-nltrophenyl)-a-ethyl-glutarimide starting material can be prepared as follows 217 g of 0 -phenyl-a-ethyl-glutarimlde are dissolved in 800 g of concentrated sulfuric acid with subsequent cooling to about -10°C and nitration Is carried out at -10°to -f10°C by slow addition of a mixed acid consisting of 110 g of concentrated suifuric acid and 110 g of 63% nitric acid. The nitration solution is stirred into ice, the separated nitro compound taken up in methylene or ethylene chloride, the solution washed with water and sodium carbonate solution until... 

A solution of 54.1 grams of 1-formyl-4-(3 -chloropropyl)-piperazine, [prepared by formylat-ing 1-(3 -hydroxypropyl)-piperazine by refluxing in an excess of methyl formate, purifying the 1-formyl-4-(3 -hydroxypropyl)-piperazine by vacuum distillation, reacting this compound with an excess of thionyl chloride at reflux and isolating the desired 1-formyl-4-(3 -chloropropyl)-piperazine by neutralization with sodium carbonate solution followed by distillation] in 200 ml of toluene is added. The reflux period Is continued for 4 hours. 

It is not necessary that the intermediate be separated from the reaction medium in the preparation of the end product. Instead, the reaction mixture, after cooling, is treated with 200 ml of water acidified with 42 ml 10% hydrochloric acid solution, and filtered. To the clear, light yellow filtrate is added dropwise a solution of 9.B g (0.07 mol) 5-nltro-2-furaldehyde in 100 ml ethyl alcohol. An orange solution of the hydrochloride results. The free base is precipitated asyellow plates by making the solution basic with saturated sodium carbonate solution. 14 g of the compound is filtered off by suction, washed with alcohol, and dried. The yield, MP 204°C to 205°C (dec.), is 53% of theoretical based on 3-(N-morpholinyl)-1,2-epoxy-propane. Recrystallization from 95% alcohol (75% recovery) raises the melting point to 206°C (dec.). 

In an initial step, the sodium derivative of ethyl (3-benzoylphenyl)cyanoecetate is prepared as follows (3-benzoylphenyl)acetonitrile (170 g) is dissolved in ethyl carbonate (900 g). There is added, over a period of 2 hours, a sodium ethoxide solution [prepared from sodium (17.7 g) and anhydrous ethanol (400 cc)], the reaction mixture being heated at... 

Prepare 26 g. of molecular sodium in a 1500 ml. round-bottomed flask (Section II,50,d, Method 1). Cover the sodium with 625 ml. of sodium-dried A.R. benzene fit the flask with an efficient reflux condenser protected from the air by means of a calcium chloride (or cotton wool) guard tube. Add 151 5 g. of diethyl adipate (Sections 111,99 and 111,100) in one lot, followed by 1 6 ml. of absolute ethyl alcohol. Warm the flask on a water bath until, after a few minutes, a vigorous reaction sets in and a cake of the sodio compound commences to separate. Keep the flask well shaken by hand during the whole of the initial reaction. After the spontaneous reaction has subsided, reflux the mixture on a water bath overnight, and then cool in ice. Decompose the product with ice and dilute hydrochloric acid (1 1) add the acid until Congo red paper is turned blue. Separate the benzene layer, and extract the aqueous layer with 100 ml. of benzene. Wash the combined extracts with 100 ml. of 5 per cent, sodium carbonate solution and 160 ml. of water dry over a KWe anhydrous magnesium sulphate. Remove the benzene under atmospheric pressure (Fig. II, 13, 4, but with modified Claisen flask), and fractionate the residue under reduced pressure. Collect the 2-carbethoxy-epelopentanone at 108-111°/15 mm. (96 g.). Upon redistillation, the product boils at 102°/H mm. 

With rapid mixing of the chloroauric acid/carbonate solution, quickly add 1ml of a 7 percent sodium ascorbate solution prepared in water. Maintain the solution cooling in an ice bath. Higher temperatures will create larger particle sizes. The color of the solution at this point will turn to a purple-red. 

The methyl ester of the acid can very conveniently be prepared by esterifying in ten parts of methyl alcohol with hydrogen chloride. After boiling for quite a short time, the cold solution, saturated with hydrogen chloride, is poured into a large volume of dilute sodium carbonate solution, and the ester, which is precipitated in solid form, is dried and recrystallised from a little dilute methyl alcohol. Other compounds which may suitably be prepared are dehydrocholic add, cholatrienic add, and cholanic add. 

Subsequent to incidents involving peroxidation of stored bottles of vinylidene chloride, a labelling procedure and list of peroxidisable compounds was prepared [3], Of the 108 compounds listed, 35 are noted as forming peroxides with ease, and these need particular care in storage and use. A revised data sheet is now available [4], and peroxide-containing residues may often be rendered innocuous by pouring into an excess of sodium carbonate solution [5],... 

Warning-. CO2 evolution. The sodium chloride-sodium carbonate solution was prepared from 185 g of sodium chloride and 110 g sodium carbonate dissolved in water to give a total volume of 1 L. 

The class of nitrolic acids (nitro-oximes) was introduced by Victor Mayer as early as 1873 with the simplest representative methylnitroUc acid (HC(N02)=N0H) °. Tscher-niak, a student of Mayer, was the first to isolate the very labile methylnitroUc acid at low temperatures, while Wieland improved the synthesis by detailing the exact reaction conditions to increase the low yields. MethylnitroUc acid can be prepared as crystalline solid from nitromethane and KNO2/H2SO4 in situ generation of nitrous acid) in water at low temperatures, followed by extraction from this weak acidic solution into ether (Scheme 17). Removal of ether yields the pme, highly unstable free acid. Salts of methylnitroUc acid, NNtM, can be generated by extracting the acid into sodium carbonate solution. ... 

Vanadium pentoxide is an intermediate in recovering vanadium from minerals (See Vanadium). Sodium polyvanadate, obtained as a red cake in one of the steps in extracting vanadium from its ores is calcined at 700°C in air to form a melt of vanadium pentoxide. Pentoxide is prepared in purified form by dissolving red cake in sodium carbonate solution followed by addition of an aqueous solution of ammonia and ammonium chloride. Ammonium metavanadate is precipitated which on decomposition at 320 to 430°C forms vanadium pentoxide. 

Alkylation of 2,4-disubstituted-5(477)-oxazolones can be conveniently performed via phase-transfer catalysis. For example, the substrate and an alkyl halide are dissolved in an organic solvent and stirred with an aqueous sodium carbonate solution containing tetrabutylammonium bromide as a phase-transfer catalyst. 4,4-(Diarylmethyl)-2-phenyl-5(4/f)-oxazolones can be prepared in one-step by dialkylation of 146 using magnesium methyl carbonate and the corresponding... 

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