Ethylene cyanohydrin

In a 5-I. flask is placed 612 g. of finely powdered sodium cyanide (passed through a meat grinder and then sifted through a 20-mesh sieve) the flask is equipped with a thermometer in a well, an efficient stirrer, and a reflux condenser (Note 4). The whole vessel is then set in a water bath into which warm and cold water can be run at will and if necessary rapidly removed. 

A mixture of 250 cc. of water and 1000 g. of pure ethylene chlorohydrin (b. p. 126-127°) is then added, the stirring is started, and the temperature of the mixture raised to 45° by external application of warm water. At this point the warm water is rapidly removed (Note 2) and the temperature of the contents of the flask carefully held at 45° by jacketing with water at a suitable temperature (33-35°). After the mixture has been held at 45° for an hour it is allowed to warm up to 48° by allowing the temperature of the water bath to rise two degrees. After an hour at 48° the temperature is raised to 50° and held at this point until the reaction is over it is necessary to raise the temperature of the bath gradually, and the end of the reaction is noted when the bath temperature reaches 50°. A period of four and a half to five hours is necessary for this last stage. 

Cold water is now placed in the water bath, while the stirrer is kept always in motion, and the temperature of the mixture is reduced to 20-22°. The mass is then filtered by suction and the sodium chloride sucked as dry as possible. This is then washed 

This is then distilled under reduced pressure from an oil bath, and the fraction boiling at 107-1090/12 mm. (116-1180/20 mm.) is collected as pure material. The yield is 700-705 g. (79-80 per cent of the theoretical amount). There is practically no residue beyond a little salt the foreruns consist of water, a small amount of unchanged ethylene chlorohydrin and some ethylene cyanohydrin. 

The sodium cyanide should be finely powdered since it never completely enters into solution, and any lumps present would run the risk of becoming coated over with sodium chloride. For the same reason, the stirring must be vigorous throughout the operation. 

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Ethylene Cyanohydrin Process. This process, the fkst for the manufacture of acryhc acid and esters, has been replaced by more economical ones. During World War I, the need for ethylene as an important raw material for the synthesis of ahphatic chemicals led to development of this process (16) in both Germany, in 1927, and the United States, in 1931. 

In the early versions, ethylene cyanohydrin was obtained from ethylene chlorohydrin and sodium cyanide. In later versions, ethylene oxide (from the dkect catalytic oxidation of ethylene) reacted with hydrogen cyanide in the presence of a base catalyst to give ethylene cyanohydrin. This was hydrolyzed and converted to acryhc acid and by-product ammonium acid sulfate by treatment with about 85% sulfuric acid. 

Processes rendered obsolete by the propylene ammoxidation process (51) include the ethylene cyanohydrin process (52—54) practiced commercially by American Cyanamid and Union Carbide in the United States and by I. G. Farben in Germany. The process involved the production of ethylene cyanohydrin by the base-cataly2ed addition of HCN to ethylene oxide in the liquid phase at about 60°C. A typical base catalyst used in this step was diethylamine. This was followed by liquid-phase or vapor-phase dehydration of the cyanohydrin. The Hquid-phase dehydration was performed at about 200°C using alkah metal or alkaline earth metal salts of organic acids, primarily formates and magnesium carbonate. Vapor-phase dehydration was accomphshed over alumina at about 250°C. 

Ethylene Cyanohydrin. This cyanohydrin, also known as hydracrylonitnle or glycocyanohydrin [109-78-4] is a straw-colored Hquid miscible with water, acetone, methyl ethyl ketone, and ethanol, and is insoluble in benzene, carbon disulfide, and carbon tetrachloride. Ethylene cyanohydrin differs from the other cyanohydrins discussed here in that it is a P-cyanohydrin. It is formed by the reaction of ethylene oxide with hydrogen cyanide. 

Like the formation of a-cyanohydrins, this reaction is catalyzed by bases or cyanide ion, but unlike the a-cyanohydrin case this reaction is not reversible, and under certain conditions it can proceed with violence. Ethylene cyanohydrin can also be prepared by the reaction of ethylene chlorohydrin and alkaH cyanides (39). 

The first U.S. plant for acrylonitrile manufacture used an ethylene cyanohydrin feedstock. This was the primary route for acrylonitrile manufacture until the acetylene-based process began to replace it in 1953 (40). Maximum use of ethylene cyanohydrin to produce acrylonitrile occurred in 1963. Acrylonitrile (qv) has not been produced by this route since 1970. 

The first commercial process for manufacture of acryHc acid (qv) and acrylates involved hydrolysis of ethylene cyanohydrin in aqueous sulfuric acid. 

Other Derivatives. Ethylene carbonate, made from the reaction of ethylene oxide and carbon dioxide, is used as a solvent. Acrylonitrile (qv) can be made from ethylene oxide via ethylene cyanohydrin however, this route has been entirely supplanted by more economic processes. Urethane intermediates can be produced using both ethylene oxide and propylene oxide in their stmctures (281) (see Urethane polymers). 

J-Chloropropionic acid has been prepared by the hydrolysis of ethylene cyanohydrin with hydrochloric acid,1 and by the oxidation of /S-chloropropionaldehyde2 or of trimethylene chlorohydrin 3 by nitric acid. 

CiHeS Dimethyl sulphide CsHsNO Ethylene cyanohydrin... 

Ethylene cyanohydrin, hi73 Ethylene diacetate, e22 Ethylenediamine, e21 Ethylene dibromide, d97 Ethylene dichloride, d226 Ethylene diglyme, bl86 (Ethylenedinitril)tetraacetic acid, el34 2,2 -Ethylenedioxybis(ethanol), t280... 

Ethylene cyanohydrin, 1 358, 404 10 639 Ethylenediamine, 2 129 8 485 as chelant, 5 709 molecular formula, 5 712t physical properties, 8 486t pK values, 8 487t prices of commercial, 8 496t sodium solubility in, 22 764 typical specifications, 8 496t Ethylenediaminetetraacetate (EDTA), 7 576... 

It is produced by polymerisation of methyl acrylate which is produced by the methanolysis of acrylonitrile or ethylene cyanohydrin. 

Ethylene cyanohydrin can be obtained by the hydrocyanation of ethylene oxide... 

The chief methods for the preparation of /3-bromopropionic acid are the action of hydrobromic acid on acrylic acid,1 on hydracrylic acid,2 and on ethylene cyanohydrin 3 the oxidation of /3-bromopropionaldehyde 4 and of trimethylene bromohydrin 5 with nitric acid. 

To the crude mixture of ammonium bromide and /3-bromo-propionic acid, prepared as described on p. 25, from 317 g. of ethylene cyanohydrin, are added 1200 cc. of carbon tetrachloride and 200 cc. of the same solvent which has been shaken with the aqueous distillates the ammonium bromide is filtered off and washed with 200 cc. of carbon tetrachloride. The watery layer, amounting to about 350 cc., is separated and shaken with 100 cc. of carbon tetrachloride. To the united carbon tetrachloride solutions are added 450 cc. of 95 per cent ethyl alcohol and 10 g. of sulfosalicylic acid or phenolsulfonic acid to act as a catalyst (Note 1). 

Ethylene cyanohydrin has been prepared by the action of ethylene oxide upon anhydrous hydrocyanic acid 1 but the majority of methods described in the literature have involved the interaction of ethylene chlorohydrin and alkali cyanide. This has been effected in the absence of a solvent by heating to ioo° in a closed vessel,2 by boiling the reagents in 50 per cent aqueous-alcoholic solution,3 by adding a concentrated aqueous solution of potassium or sodium cyanide to a boiling solution of ethylene chlorohydrin in absolute alcohol,4 and in aqueous solution at 45 °.5... 

Ethylene Cyanohydrin or /3-Hydroxypropio-nitrile, HO.CH8.CH2.CN mw 71.08, N 19.71% poisonous straw-colored Uq, sp gr 1.0404 at 25°/4, fr p -46°, bp 227-28°(dec), vapor pressure 20mm at 117 miscible with w, acet, ethanol, chlf, methyl-ethyl ketone si sol in eth insol in benz, CC14 naphtha. It can be prepd by interaction of ethylene oxide with... 

Cupriethylenediamine Solution Cupriethylenediamine Solution Copper Cyanide Copper Iodide Cyanoacetic Acid Potassium Cyanide Calcium Cyanide Cyanoacetic Acid Benzonitrile Ethylene Cyanohydrin Acrylonitrile... 

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