in the presence of a catalyst methanesulfonic acid or hypophosphorous acid under nitrogen at 160 u00b0 240 u00b0 while continuously distilling off the water of reaction or the alcohol formed during which if desired the pressure may be reduced in order to complete the reaction the subsequent quaternization is also carried out by known methods according to the invention the preferred procedure involves treating the ester if desired with the additional use of a solvent preferably of one of the general formula 4 together with in particular methoxypropanol 1 2 propylene glycol and or dipropylene glycol at 60 u00b0 90 u00b0 c with equimolar amounts of the quaternizing agent with stirring if desired under pressure and monitoring the completion of the reaction by controlling the total amine number preferably the amount of solvent is selected in such a manner that it corresponds to the amount used in the end recipe examples of additionally used quaternizing agents are short chained dialkyl phosphates and dialkyl sulfates such as in particular dimethyl sulfate diethyl sulfate dimethyl phosphate diethyl phosphate and short chain halogenated hydrocarbons in particular methyl chloride according to the invention the additionally used compounds include those of the general formula 3 str5 in which ao is the radical ch ch 3 ch 2 o and or the radical ch 2 ch 2 o and in which r 1 r 2 r 3 r 4 which are identical or different from one another are the radicals h o ch r ch 2 m in which r is h or a methyl or ethyl radical and m is 1 10 the sum of all m being preferably between 4 and 20 and r 6 and r 7 which are identical or different form one another are each h ch.