Calcium ethoxide

Reaction of epoxides with isocyanates. Calcium ethoxide is the most efficient catalyst for the reaction of phenyl isocyanate (1) with the epoxide (2) to form the 2-oxazolidinone (3). ... 

CadmiumfO), 52 Calcium ethoxide, 52 Camphene, 50, 400, 401 Camphor, 217 Camphorquinone, 55 Cannizzaro reaction, 77-78 Carbamates, 346, 377, 378 a-Carbinollactams, 330 Carbodiimides, 45 ( arboelhoxycarbenc, 313... 

Epoxides react with isocyanates at elevated temperatures to give 2-oxazolidinones 347 . A similar reaction is observed with phenylcarbonyl isocyanate. The reaction is catalyzed by palladium (o)-triisopropyl phosphite catalysts, lithium salt-phosphine adducts, aluminum trichloride or calcium ethoxide. The reaction can formally be regarded as interception of the thermally generated 1,3-dipolar intermediates, and it was shown that the reaction does not occur, unless the catalyst initiates ring opening... 

Anastopoulos, G., Dodos, G.S., et al., 2013. Biodiesel production by ethanolysis of various vegetable oils using calcium ethoxide as a solid base catalyst. International Journal of Green Energy 10 (5), 468-481. 

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. 

Calcium Methylate Ethylate and Ethylate. Calcium methoxide [2556-53-8] and ethoxide [2914-17-2], Ca(OCH2)2 and Ca(OC2H )2, are white powders soluble in the corresponding alcohol (max concentration 1%). They are packaged and stored like the magnesium alkoxides. 

The chemistry of ethyl alcohol is largely that of the hydroxyl group, namely, reactions of dehydration, dehydrogenation, oxidation, and esterification. The hydrogen atom of the hydroxyl group can be replaced by an active metal, such as sodium, potassium, and calcium, to form a metal ethoxide (ethylate) with the evolution of hydrogen gas (see Alkoxides, metal). 

The absolute ethyl alcohol employed in the condensation was refluxed over calcium oxide for 20 hours and finally distille from magnesium ethoxide. 

The procedure given above is essentially a large-scale adaptation of that of Filachione.2 Bromoacetal has been prepared by the bromination of acetal directly,3 or in the presence of calcium carbonate 4 by action of sodium ethoxide on a,/3-dibromodiethyl ether by bromination of paraldehyde followed by action of ethyl alcohol 6 and by the action of ethyl alcohol on bromoacetal-dehyde.7... 

A. Triethyl oxalylsuccinate. In a 2-1. three-necked flask equipped with a sealed stirrer and a reflux condenser bearing a calcium chloride drying tube is placed 356 ml. (276 g., 6.00 moles) of anhydrous ethanol (Note 1). Sodium (23 g., 1.0 g. atom) is added in small portions at a rate sufficient to keep the ethanol boiling. External heating is required to dissolve the last portions of the metal. After all the sodium has dissolved, the excess ethanol is removed by distillation at atmospheric pressure as the mixture becomes pasty, dry toluene is added in sufficient amounts to permit stirring and to prevent splattering of the salt. Distillation and addition of toluene is continued until all the ethanol is removed and the contents of the flask reach a temperature of 105° (Note 2). The sodium ethoxide slurry is cooled to room temperature and 650 ml. of anhydrous ether is added, followed by 146 g. (1.00 mole of diethyl oxalate. To the yellow solution there is added 174 g. (1.00 mole) of diethyl succinate, and the mixture is allowed to stand at room temperature for at least 12 hours. 

A. Z,5-DicaThelhoxy-l,4-cyclohexanedione. A solution of sodium ethoxide is prepared by adding small pieces of sodium (92 g., 4 g. atoms) as rapidly as possible to 900 ml. of commercial absolute ethanol contained in a 3-1., three-necked, round-bottomed flask equipped with two stoppers and a reflux condenser fitted with a drying tube packed with calcium chloride and soda lime. The reaction is completed by heating the mixture under reflux for 3-4 hours (Note 1). To the hot solution is added diethyl succinate (348.4 g., 2 moles) (Note 2) in one portion Caution Exothermic reaction), and the mixture is heated under reflux by maintaining the original bath temperature for 24 hours. A thick pink-colored precipitate is formed almost immediately and remains throughout the reaction. 

Sodium ethoxide is prepared from 12.0 g. (0.52 gram atom) of sodium and 300 ml. of anhydrous ethanol in a 1-1. three-necked round-bottomed flask fitted with a reflux condenser carrying a calcium chloride tube. After the sodium has dissolved completely, the condenser is arranged for distillation under reduced pressure and the excess ethanol is removed by heating the flask on a steam bath while the system is maintained at the pressure obtained with an ordinary aspirator (Note 1). 

As rapidly as possible, after removal of the ethanol, the flask is fitted with a rubber-sealed stirrer, a dropping funnel, a distilling head containing a thermometer, and a condenser arranged for distillation into a flask protected by a calcium chloride tube. There are then added 300 ml. of dry diethyl carbonate, 80 ml. of dry toluene, and 58.5 g. (0.50 mole) of phenylacetonitrile (Note 2). The flask is heated, with good stirring, and the cake of sodium ethoxide soon dissolves. When distillation has started, dry toluene is added dropwise at about the same rate that the distillate is collected. Approximately 200-250 ml. of toluene should be added in a period of 2 hours (Note 3) while stirring and distillation are continued. 

B. a-Morpholinostyrene (2). A mixture of 75.0 g. (0.625 mole) of acetophenone, 81.0 g. (0.930 mole) of morpholine (Note 3), 200 mg. of p-toluenesulfonic acid, and 250 ml. of benzene is placed in a 500-ml., round-bottomed flask equipped with a water separator (Note 4), under a reflux condenser protected by a calcium chloride drying tube. Separation of water begins with reflux and is complete after 180 hours. After the mixture is cooled to room temperature, 200 mg. of sodium ethoxide is added for... 

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