Sodium ethoxide solution

While the sodium ethoxide solution is cooling, prepare a solution of 7 7 g. of finely powdered iodine in 60 ml. of ether. When this solution is ready, add 9 ml. (9 6 g.) of ethyl malonate to the ethanolic sodium ethoxide solution, mix w ell and then allow to stand for 30-60 seconds not longer) then cautiously add the ethereal solution of the iodine, mixing thoroughly during the addition in order to avoid local overheating by the heat of the reaction. (If, after the ethyl malonate has been added to the sodium ethoxide, a considerable delay occurs before the iodine is added, the yield of the final product is markedly decreased.)... 

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). 

Wolff - Kishner reduction of aldehydes and ketones. Upon heating the hydrazoiie or semicarbazone of an aldehyde or ketone with potassium hydroxide or with sodium ethoxide solution (sealed tube), the corresponding hydrocarbon is obtained ... 

Ethyl phenylethylmalonate. In a dry 500 ml. round-bottomed flask, fitted with a reflux condenser and guard tube, prepare a solution of sodium ethoxide from 7 0 g. of clean sodium and 150 ml. of super dry ethyl alcohol in the usual manner add 1 5 ml. of pure ethyl acetate (dried over anhydrous calcium sulphate) to the solution at 60° and maintain this temperature for 30 minutes. Meanwhile equip a 1 litre threenecked flask with a dropping funnel, a mercury-sealed mechanical stirrer and a double surface reflux condenser the apparatus must be perfectly dry and guard tubes should be inserted in the funnel and condenser respectively. Place a mixture of 74 g. of ethyl phenylmalonate and 60 g. of ethyl iodide in the flask. Heat the apparatus in a bath at 80° and add the sodium ethoxide solution, with stirring, at such a rate that a drop of the reaction mixture when mixed with a drop of phenolphthalein indieator is never more than faintly pink. The addition occupies 2-2 -5 hoius continue the stirring for a fiuther 1 hour at 80°. Allow the flask to cool, equip it for distillation under reduced pressure (water pump) and distil off the alcohol. Add 100 ml. of water to the residue in the flask and extract the ester with three 100 ml. portions of benzene. Dry the combined extracts with anhydrous magnesium sulphate, distil off the benzene at atmospheric pressure and the residue under diminished pressure. C ollect the ethyl phenylethylmalonate at 159-160°/8 mm. The yield is 72 g. 

With the more acidic 2-acetamido-4-R-thiazoles. using the weaker base NaOH as condensation agent, a mixture of ring (45) and exocyclic N-alkylation (46) may be observed (Scheme 33) (121). Reaction of 2-acetamido-4-methylthiazole in alcoholic sodium ethoxide solution with a variety of alkylating agents has been reported (40-44). 

Iodoveratrole has been prepared by iodination of veratrole in the presence of mercuric oxide and by methylation of 4-iodoguaiacol with methyl iodide in alcoholic sodium ethoxide solution. ... 

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... 

With l,l-bis(4, 4"-dialkylamino)phenylethene (12.105) azo coupling takes place in the 2-position (Wizinger and Cyriax, 1945, 1957). Deprotonation of the primary adduct to give the red l,l-bis(dialkylaminophenyl)-2-arylazo-ethene 12.106 takes place rapidly after addition of a sodium ethoxide solution (Scheme 12-53). 

The sodium ethoxide solution is preptired from the reaction of 9.2 g. (0.40 mole) of sodium with 11. of absolute ethanol and is standardized by titration with aqueous 0.1 N hydrochloric acid. The appropriate volume of the solution to give 0.280 mole of base is used. 

Ttie sodium ethoxide solution is convenioiitly prepared as follows. Place 46 g. of dean sodium (Section III,7, Note 7) in a 2 litre round-bottomed flask provided with a 25 cm. double surface condenser. The apparatus must be perfectly dry. Cool the flask in a bath of crushed ice. Add 800 ml. of super-dry ethyl alrohol in one operation. A vigorous reaction will ensue, but it will remain under eontool. When the initial reaction is over, remove the ice bath and allow the le ual sodium to react. If smaU quantities of sodium remain, warm the flask water bath until solution is complete. 

For the preparation of methyl orthoformate, solid sodium methoxide, methanol and chloroform were mixed together. The mixture boiled violently and then exploded [1]. The analogous preparation of ethyl orthoformate [2] involves the slow addition of sodium or sodium ethoxide solution to a chloroform-ethanol mixture. The explosion was caused by the addition of the solid sodium methoxide as one portion. See Sodium, etc., above... 

A slurry of sodium nitromethanoate in excess sodium ethoxide solution forms a (presumably even more) explosive salt on treatment with nitric oxide. It is claimed the parent acid is O2NCH2N2O2H. 

Reaction of iodine with the lithium heptynide in liquid ammonia to give (explosive) 1-iodoheptyne may lead to formation of nitrogen triiodide as a black precipitate. Low temperatures minimise the formation, and it may be destroyed by adding sodium ethoxide solution. 

A 2-1. three-necked flask is mounted on a steam bath and fitted with a reflux condenser, a separatory funnel, and an efficient sealed stirrer. In the flask is placed 600 cc. of absolute alcohol, and to this is added gradually 46 g. (2 gram atoms) of clean sodium cut into small pieces.1 The sodium ethoxide solution is stirred and cooled to room temperature, after which 267 g. (260 cc., 2.05 moles) of ethyl acetoacetate (Note 1) is added slowly through the separatory funnel. The reflux condenser is then replaced by a short still head, and the alcohol is removed by distillation at approximately room temperature and under the pressure of a water pump. When approximately half the alcohol has been removed, sufficient sodium enolate precipitates so that stirring has to be discontinued. When the residue appears dry (after about two hours) the last traces of alcohol are removed by heating for an hour on the steam bath under a pressure of 2 mm. The flask is allowed to cool to room temperature under reduced pressure. 

From the completion of addition of the sodium ethoxide solution to the steam distillation, fast work is advantageous, and all equipment should be in readiness before the addition is started. Allowing the solution to stand before addition of the tartaric acid may cause darkening and formation of gummy material. It is important that the solution should remain slightly acid during the steam distillation. 

To get sodium ethoxide solution from sodium ethoxide powder and ethanol, mix it slowly in a glass or stainless container and use all safety equipment (gloves, eyewear, and ventilation). Always add powder to the liquid ( ) and if it gets hot to the touch, slow down. Both chemicals absorb water from the atmosphere, so choose your location and the day appropriately (http //wiki.answers.com/). 

The sodium ethoxide solution was prepared by dissolving 2.3 g of sodium in 50 tit of anhydrous ethanol and was used immediately. 

The concentrated sodium ethoxide solution must be kept hot throughout the process otherwise a voluminous precipitate separates and the mixture congeals. 

Recently, an experimental reappraisal of this rearrangement was reported, in which cubyl phenyl ketone tosylhydrazone (1) was thermolyzed in an ethanolic sodium ethoxide solution to give a good yield of a 1.5 1 mixture of 9-ethoxy-9-phenylhomocubane (3) and 9-ethoxy-l-phenylhomocubane (4).3 In addition, photolysis (mercury arc, Pyrex filter) of cubylphenyldi-azomethane (2) in ethanol also produced a similar result.3... 

B. N,N, N"-Tris(p-tolysulfonyl)diethylenetriamine-N,N"-disodium salt (2). A 3-1., three-necked, round-bottomed flask is equipped with a mechanical stirrer, reflux condenser, and addition funnel. In the flask are placed 11. of absolute ethanol and 425 g. (0.75 mole) of triamine 1 under nitrogen. The stirred slurry is heated to reflux, the heat source is removed, and 1000 ml. of 1.5N sodium ethoxide solution (Note 2) is added through the addition funnel as rapidly as possible. The solution is then decanted from any undissolved residue into an Erlenmeyer flask. The disodium salt 2, which crystallizes on standing overnight, is filtered under nitrogen, washed with absolute ethanol, and dried in a vacuum oven at 100°. The yield is 400-440 g. (87-96%). 

The checkers report that the sodium ethoxide solution should be used promptly in order to avoid the formation of colored impurities. 

The anhydrous, deoxygenated sodium ethoxide solution readily dehydrates carbinolamide 2 to the acyldihydropyridine 3 but prevents hydrolysis or oxidation of 3. Base-catalyzed double bond migrations can lead to 4, the imine of a /3-diketone, and the acetyl fragment can then be cleaved. Addition of water to the reaction causes hydrolysis of the cross-conjugated dienamine 5 to diketone 6 which then cyclizes. 

Enough sodium ethoxide solution for four runs can be made in a 500-ml. flask by adding 18.4 g. of sodium portionwise to 300 ml. of absolute ethanol. 

Aryl alkyl ketones are readily prepared by the Friedel-Crafts acylation process (see Section 6.11.1, p. 1006) and their Clemmensen reduction constitutes a more efficient procedure for the preparation of monoalkylbenzenes than the alternative direct Friedel-Crafts alkylation reaction (see below). Alternatively aldehydes and ketones may be reduced to the corresponding hydrocarbon by the Wolff-Kishner method which involves heating the corresponding hydrazone or semicarbazone with potassium hydroxide or with sodium ethoxide solution. 

Examples of the preparation of alkyl benzyl ethers by the Williamson synthesis are included in Section 5.6.2, p. 583. An example of an alkyl phenyl ether is provided by the synthesis of phenacetin (Expt 6.109) where p-aminophenol is first converted into its Af-acetyl derivative by reaction with slightly more than one equivalent of acetic anhydride. Treatment of the product with ethanolic sodium ethoxide solution followed by ethyl iodide then yields the ethyl ether of AT-acetyl-p-phenetidine (phenacetin). This compound is biologically active and has been widely employed for example as an antipyretic and analgesic however, owing to undesirable side reactions, its use is now restricted. 

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