Process for preparation of pure alkyl esters from alkali metal salt of carboxylic acid

摘要

The dehydrated alkali metal salts of carboxylic acid are dissolved in the alcohol such as methanol or ethanol or butanol to make their solution in corresponding alcohol. The solution alcohol is further treated with carbon dioxide under pressure or at atmospheric pressure at elevated temperature such as 150 to 200� C. The carboxylic acid gets converted into corresponding alkyl ester and calcium carbonate or sodium carbonate or potassium carbonate as the byproduct. Calcium lactate or sodium lactate or sodium acetate or sodium benzoate or sodium salicylate as alkali metal salt solution prepared in methanol or ethanol or butanol when treated with carbon dioxide under pressure or at atmospheric pressure at elevated temperature gets converted to methyl lactate or ethyl lactate or methyl acetate or methyl benzoate or methyl salicylate as product.