Preparation of tocopheral carboxylates or tocotrienyl esters by acid-catalyzed reaction with carboxylic acids

摘要

A process for preparing tocopheryl esters or tocotrienyl esters by acid-catalyzed esterification of a tocopherol or a tocotrienol in a solvent while stirring at elevated temperature, which comprises;a) carrying out the esterification with the appropriate carboxylic acid,;b) carrying out the esterification with from 2.5 to 6 mol of the carboxylic acid in an aliphatic, cycloaliphatic or aromatic hydrocarbon boiling in the range from 80 to 200 C.,;or else with from 1.0 to 2.5 mol of the carboxylic acid in a mixture consisting of an aliphatic or cycloaliphatic hydrocarbon boiling in the range from 80 to 200 C. and a cyclic carbonate of the formula II or a -lactone of the formula III ;where R¹, R² and R³ are each H or lower alkyl, and R⁴ is H, lower alkyl, phenyl or methoxymethyl, as solvent,;c) using a nonoxidizing strong inorganic or organic acid, preferably sulfuric acid, boroxalic acid or benzene- or toluenesulfonic acids, in catalytic amounts as acid catalyst, and;d) continuously removing the water formed in the reaction by azeotropic distillation during the reaction.