Diethyl carbonates

Petroleum Naphtha Distillation range Below 120 C Below 128 C Above 180 C Dryness at 20 C 

Miscible without turUdity with 20 vols 00 B4 gasoline 

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Now run in a solution of 52 g. (53-5 ml.) of pure diethyl carbonate (1) in 70 ml. of anhydrous ether, with rapid stirring, over a period of about one hour. A vigorous reaction sets in and the ether refluxes continually. When the diethyl carbonate has been added, heat the flask on a water bath with stirring for another hour. Pour the reaction mixture, with frequent shaking, into a 2 litre round-bottomed flask containing 500 g. of crushed ice and a solution of 100 g. of ammonium chloride in 200 ml. of water. Transfer to a separatory funnel, remove the ether layer, and extract the aqueous solution with two 176 ml. portions of ether. Dry... 

Commercial diethyl carbonate may be purified by the following process. Wash 100 ml. of diethyl carbonate successively with 20 ml. of 10 per cent, sodium carbonate solution, 20 ml. of saturated calcium chloride solution, and 25 ml. of water. Allow to stand for one hour over anhydrous calcium chloride with occasional shaking, filter into a dry fiask containing 5 g. of the same desiccant, and allow to stand for a further hour. Distil and collect the fraction boiling at 125-126°. Diethyl carbonate combines with anhydrous calcium chloride slowly and prolonged contact should therefore be avoided. Anhydrous calcium sulphate may also be used. 

The following tertiary alcohols may be prepared from the appropriate Grignard reagent and diethyl carbonate in yields of 75-80 per cent. 

Chloroform undergoes oxidation to the very poisonous phosgene upon exposure to light and air. Commercial specimens are therefore stored in brown bottles and contain 1-2 per cent, of alcohol the latter converts the toxic phosgene into the harmless substance diethyl carbonate ... 

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. 

From the mono-halogenated hydrocarbon. The halogenated hydrocarbon is converted into the Grignard reagent and the latter allowed to react with diethyl carbonate, for example ... 

Chiral 2-oxazolidones are useful recyclable auxiliaries for carboxylic acids in highly enantioselective aldol type reactions via the boron enolates derived from N-propionyl-2-oxazolidones (D.A. Evans, 1981). Two reagents exhibiting opposite enantioselectivity ate prepared from (S)-valinol and from (lS,2R)-norephedrine by cyclization with COClj or diethyl carbonate and subsequent lithiation and acylation with propionyl chloride at — 78°C. En-olization with dibutylboryl triflate forms the (Z)-enolates (>99% Z) which react with aldehydes at low temperature. The pure (2S,3R) and (2R,3S) acids or methyl esters are isolated in a 70% yield after mild solvolysis. 

In a reaction related to the mixed Claisen condensation nonenolizable esters are used as acylatmg agents for ketone enolates Ketones (via their enolates) are converted to p keto esters by reaction with diethyl carbonate... 

Dimethyl and diethyl carbonates ate shipped in nonretumable 208-L (55-gal) polyethylene dmms with carbon steel overpack or high density polethylene dmms. For bulk shipments, insulated stainless steel tank containers and tmcks provide secure protection. Diethylene glycol bis(aHyl) carbonate is shipped in dmms as above. 

Finar and coworkers (B-76MI40402) have made a detailed study of the pyrazolyl Grignard reagent (505). In addition to alcohols and ketones, the hydrocarbons (506) and (507) could be isolated, the first by heating the Grignard reagent (505) and the second by reaction with diethyl carbonate. 

The checkers obtained 2-am1noethanol, diethyl carbonate, and anhydrous sodium methoxide from the Aldrich Chemical Company. 

Diethyl carbonate Carbonic acid, diethyl ester (8,9) (105-58-8)... 

The time necessary for completion of the reaction may vary from 0.5 to 4 hours, depending on the actual activity of the alumina. The progress of conversion should be monitored by infrared analysis of a concentrated sample of the solution. Stirring should be continued for 15 minutes after the nitroso band at 1540 cm. has disappeared. A strong diazo band at about 2100 cm. will then be present. The carbonyl band at 1750 cm. initially due to nitrosocarbamate, will usually not disappear completely during the reaction, because some diethyl carbonate is formed in addition to carbon dioxide and ethanol. Diethyl carbonate is removed during the work-up procedure. 

The ethyl ester has been obtained in. 70 per cent yield from the reaction of a-naphthyhnagnesium bromide and diethyl carbonate. Loder and Whitmore J. Am. Chem. Soc. 57, 2727 (1935). 

The electrolyte used is 1 molar LiPF dissolved in a mixture of 30% ethyl carbonate (EC) and 70% diethyl carbonate (DEC) by volume. This electrolyte IS easy to use because it will self-wet the separator and eleetrodes at atmospheric pressure. The electrolyte is kept under an argon atmosphere in the glove-box. The moleeules of electrolyte solvents, like EC and DEC, have in-plane dimensions of about (4 A x 5 A) to (6 A x 7 A). These molecules are normally larger than the openings of the micropores formed in the region 3 carbons (Fig. 2) as described in section 5. 

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