Ethyl hydrogenation

When concentrated sulphuric acid is added to ethanol, the mixture becomes hot owing to the formation of ethyl hydrogen sulphate, the yield of which is increased if the mixture is then gently boiled under reflux ... 

If the mixture contains an excess of ethanol, and is heated to 140°, the ethyl hydrogen sulphate reacts with the ethanol, giving diethyl ether And regenerating the sulphuric acid ... 

If the mixture contains a considerable excess of sulphuric acid and is heated to 160-170 , the ethyl hydrogen sulphate breaks down, giving ethylene and again regenerating the sulphuric acid. 

This ion (1) can react in three ways, according to the conditions. (a) reaction with the HSOj may give ethyl hydrogen sulphate... 

Pure ethyl hydrogen sulphate is difficult to prepare, as it is an oily liquid, very soluble in water, and easily hydrolysed. It is therefore usually isolated as the potassium salt, since potassium ethyl sulphate crystallises well from water, and is not readily hydrolysed in neutral or weakly alkaline solution. 

CH3COOH + HOC2H5 - CH3GOOC2H3 + H2O If, however, concentrated sulphuric acid is present, the water is absorbed, the back reaction prevented, and a high yield of ethyl acetate is obtained. In practice the reaction is not so simple. It was formerly supposed that, since the sulphuric acid is usually added to the alcohol, ethyl hydrogen sulphate and water are formed, the latter being absorbed by the excess of sulphuric acid, A mixture of ethanol and acetic acid is then added to the ethyl hydrogen sulphate,... 

Diethyl ether may be prepared from ethyl alcohol by the sulphuric acid process. A mixture of alcohol and sulphuric acid in equimolecular proportions is heated to about 140° and alcohol is run in at the rate at which the ether produced distils from the reaction mixture. Ethyl hydrogen sulphate (or ethyl sulphuric acid) is first formed and this yields ether either by reacting directly with a molecule of alcohol or by the formation and alcoholysis of diethyl sulphate (I) ... 

If the temperature is allowed to rise to 170°, much of the ethyl hydrogen sulphate decomposes into ethylene ... 

The sulphuric acid and ethyl hydrogen sulphate required in reactions 1 and 3 respectively are regenerated in reactions 2 and 4, but the water formed is retted in the acid mixture and ultimately results in such a dilution that the caiversion into ether is no longer efficient. Furthermore, some ethylene is always formed this partly polymerises to give materials capable of reacting with sulphuric acid and reducing it to sulphur dioxide. In industrial practice, sulphuric acid is sufficient for the production of about 200 parts of ether. 

Diethyl sulfate can be prepared by a vahety of methods. When ethyl hydrogen sulfate is heated with sodium chloride to 80°C, hydrogen chloride is hberated. The resulting reaction mixture is then distilled at 1.33—2.00 kPa (10—15 mm Hg) at a maximum ketde temperature of 190°C to give diethyl sulfate in 90% yield (95). 

Passing a stream of nitrogen at 95—100°C through a reaction mixture of ethyl ether and 30 wt % oleum prepared at 15°C results in the entrainment of diethyl sulfate. Continuous operation provides a >50% yield (96). The most economical process for the manufacture of diethyl sulfate starts with ethylene and 96 wt % sulfuric acid heated at 60°C. The resulting mixture of 43 wt % diethyl sulfate, 45 wt % ethyl hydrogen sulfate, and 12 wt % sulfuric acid is heated with anhydrous sodium sulfate under vacuum, and diethyl sulfate is obtained in 86% yield the commercial product is >99% pure (97). 

Absorption of ethylene in concentrated sulfuric acid to form monoethyl sulfate (ethyl hydrogen sulfate) and diethyl sulfate ... 

The absorption is carried out by countercurrent passage of ethylene through 95—98% sulfuric acid in a column reactor at 80°C and 1.3—1.5 MPa (180—200 psig) (41). The absorption is exothermic, and cooling is required (42) to keep the temperatures down and thereby limit corrosion problems. The absorption rate increases when ethyl hydrogen sulfate is present in the acid (43—46). This increase is attributed to the greater solubiUty of ethylene in ethyl hydrogen sulfate than in sulfuric acid. 

Diethyl ether is the principal by-product of the reaction of ethyl alcohol with diethyl sulfate. Various methods have been proposed to diminish its formation (70—72), including separation of diethyl sulfate from the reaction product. Diethyl sulfate not only causes an increase in ether formation but is also more difficult to hydroly2e to alcohol than is ethyl hydrogen sulfate. The equiUbrium constant for the hydrolysis of ethyl hydrogen sulfate is independent of temperature, and the reaction rate is proportional to the hydrogen ion concentration (73—75). 

Boil a little of the solution of the salt with a few drops of dilute hydrochloric acid for a minute and add barium chloride. A precipitate of barium sulphate is formed, as, on boiling ethyl hydrogen sulphate in aqueous solution, it is decomposed into sulphuric acid and alcohol (see Appendix, p. 234). 

Ethyl oxalate Sodium ethylate Hydrogen chloride Hydrogen... 

Partial esters are named via insertion of the term hydrogen (separated by spaces) between the ester radical name and the parent name. For example, CH3P(OH)OC2H5 is named ethyl hydrogen methylphosphonite or ethyl hydrogen methanephosphonite. 

C 7H,203 5675-70-7) see Bisantrene (R)-(-i)-tetrahydrofuran-2-carboxylic acid (CjHgOj 87392-05-0) see Faropenem sodium ( )-tetrahydrofuran-2-carboxylic acid (CjHgOg 16874-33-2) see Alfuzosin Faropenem sodium tetrahydro-2-furancarboxylic acid anhydride with ethyl hydrogen carbonate (CgHijO, 167391-50-6) see Alfuzosin... 

Ethyl hydrogen sebacate, 21, 48 electrolysis of, 21, 48 Ethyl isothiocyanate, 21, 82 Ethyl lactate, 21, 71 Ethyl laurate, 20, 69 Ethyl linoleate, 22, 77 Ethyl linolenate, 22, 83 Ethyl malonate, 23, 16 Ethyl mercaptan, 22, 59 Ethyl 1V-methyl-/3-aminopropionate, 20, 37... 

Ethyl Hydrogen Methylphosphonothioate 0-Ethyl Hydrogen Methylphosphonothionate O-Ethyl Methylphosphonothioate O-Ethyl Methylphosphonothioic Acid O-Ethyl Methylthiophosphonate... 

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