Diethyl sulphate

CH3CH2OCH2CH2OH. A colourless liquid with a pleasant odour b.p. 135 C. Manufactured by heating ethylene oxide with ethanol and a catalyst, or by treating ethylene glycol with diethyl sulphate and sodium hydroxide. Used extensively as a solvent in nitrocellulose lacquers. 

C2He04S, Et0)(H0)S02. Oily acidic liquid. Soluble in water and slowly hydrolysed by it to ethanol and sulphuric acid. Prepared by passing ethene into concentrated sulphuric acid or by heating ethanol and sulphuric acid. Gives ethene when heated alone, and diethyl sulphate when heated with ethanol at 140 C. Forms crystalline metallic salts which are soluble in water. 

Diethyl sulphate, b.p. 210° (decomp.), does not ordinarily react so vigor ously as dimethyl sulphate, but is nevertheless of great value for ethylations. It is somewhat leas poisonous than the methyl analogue, but the same pre cautions should be taken. Both sulphates should be stored in glass stoppered bottles sealed with paraffin wax, for they attack cork. 

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) ... 

Successful results have been obtained (Renfrew and Chaney, 1946) with ethyl formate methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec.-butyl and iso-amyl acetat ethyleneglycol diacetate ethyl monochloro- and trichloro-acetates methyl, n-propyl, n-octyl and n-dodecyl propionates ethyl butyrate n-butyl and n-amyl valerates ethyl laurate ethyl lactate ethyl acetoacetate diethyl carbonate dimethyl and diethyl oxalates diethyl malonate diethyl adipate di-n-butyl tartrate ethyl phenylacetate methyl and ethyl benzoates methyl and ethyl salicylates diethyl and di-n-butyl phthalates. The method fails for vinyl acetate, ieri.-butyl acetate, n-octadecyl propionate, ethyl and >i-butyl stearate, phenyl, benzyl- and guaicol-acetate, methyl and ethyl cinnamate, diethyl sulphate and ethyl p-aminobenzoate. 

Methyl and ethyl ethers of phenols are most conveniently prepared by alkylation with dimethyl sulphate and diethyl sulphate respectively in weakly alkaline solution, for example ... 

CAUTION. Diethyl sulphate is poisonous, but to a less degree than dimethyl sulphate. Similar precautions should, however, be taken (see above). 

After all the diethyl sulphate has been introduced, reflux the mixture gently for 2 hours with stirring. Transfer the diluted reaction mixture to a separatory funnel, run oflF the lower aqueous layer, wash successively with water, dilute sulphuric acid (twice), and with water until the washings are neutral to litmus. Dry over anhydrous calcium chloride or magnesium sulphate, and distil. Collect the phenyl ethyl ether (a colourless liquid) at 168-170°. The yield is 50 g. 

I) If the diethyl sulphate is dark in colour, it should be washed in the fume cupboard with ice water, then with sodium bicarbonate solution until all free acid is removed, and distilled under reduced pressure. 

Diethylene triamine Diethyl ether, see Ethyl ether Di(2-ethylhexyl)phthalate, see Di-sec-octyl phthalate Diethyl ketone Diethyl phthalate Diethyl sulphate Difluorodibromomethane Diglycidyl ether (DGE)... 

Diethyl sulphate and dimethyl sulphate Lab method using Tenax sorbent tube, thermal desorption and gas chromatography with mass spectrometry 89... 

O-Alkylation of phenols Phenol/cresols/catechols, alkyl halides/dimethyl sulphate/diethyl sulphate... 

Moist diethyl sulphate was stored in an iron reservoir, which detonated after a little while. This accident was explained by the hydrolysis of the sulphate present that gives rise to the formation of sulphuric acid. By reacting with iron, sulphuric acid formed hydrogen that caused the overpressure responsible for the detonation. 

When diethyl sulphate comes into contact with potassium tert-butylate, this gives rise to immediate ignition. 

---