GB795440A - Method for making anhydrous alkali metal alcoholates - Google Patents

Abstract

Anhydrous alcoholic solutions of alkali metal alcoholates are obtained by forcing a liquid monohydric alcohol containing at least 2 carbon atoms to rise through a bed of at least 0.1 molar excess of solid particles of sodium hydroxide or potassium hydroxide at a temperature between 70 DEG and 200 DEG C., at which the alcohol is liquid, and recovering an alcohol solution of the anhydrous alkali metal alcoholate from above the bed, while drawing off concentrated aqueous alkali metal hydroxide from beneath the bed, the bed being maintained at substantially constant volume by addition of solid alkali to replace that which is consumed and withdrawn. Suitable alcohols are, for example, aliphatic alcohols containing 2 or more carbon atoms, cyclo-aliphatic alcohols and aryl aliphatic alcohols, such as benzyl alcohol, and also substituted alcohols. The alkali metal alcoholates may be separated from the solutions by conventional distillation and evaporation methods. In the examples: (a) a glass column containing glass rings is filled with potassium hydroxide pellets and 3-pentanol is fed in from the bottom; anhydrous potassium alcoholate solution is obtained from the top of the column; (b) the process of (a) is repeated using (i) ethanol, (ii) 2-propanol, (iii) diethylaminoethanol, (iv) benzyl alcohol, and (v) 2-butanol to give the corresponding potassium alcoholates, and (c) the process of (a) is repeated using sodium hydroxide instead of potassium hydroxide and the following alcohols: (i) dipropylene glycol monophenyl ether, and (ii) tetrapropylene glycol monoethyl ether to give the corresponding sodium alcoholates.