Process for the purification of tertiary amines from primary and secondary amines

Process for the purification of tertiary amines of the general formula I in which R , R and R are C1- to C20-alkyl, C2- to C20-dialkylamino-C 2- to C10-alkyl, C1- to C10-alkoxy-C2- to C10-alkyl, C2- to C20- hydroxyalkyl, C3- to C12-cycloalkyl, C4- to C20-cycloalkylalkyl, C2- to C20-alkenyl, C4- to C30-dialkylaminoalkenyl, C3- to C30-alkoxyalkenyl, C3- to C20-hydroxyalkenyl, C5- to C20-cycloalkylalkenyl, or aryl or C7- to C20-aralkyl which are optionally substituted one to five times by C1- to C8-alkyl, C2- to C8-dialkylamino, C1- to C8-alkoxy, hydroxyl, C3- to C8-cycloalkyl, C4- to C12-cycloalkylalkyl from primary and tertiary amines, which is characterised in that the mixture of tertiary, primary and secondary amine to be purified is treated at temperatures from 0 to 200 DEG C and pressures from 1 to 200 bar with carboxylic acid esters of the general formula II in which R and R are hydrogen, C1- to C20-alkyl, C3- to C12-cycloalkyl, C4 - to C20-cycloalkylalkyl, or aryl or C7- to C20-aralkyl which are optionally substituted one to five times by C1- to C8-alkyl, C3- to C8-cycloalkyl or C4- to C12-cycloalkylalkyl.