The present invention relates to a process for the preparation of an ester in a reactor, wherein at least one of at least two different catalysts is an electron donor and a further catalyst is a sulphur-containing proton donor； a device, a process for the preparation of a thermoplastic composition comprising the ester prepared according to the invention, a process for the production of a shaped article comprising the ester according to the invention or the thermoplastic composition according to the invention, a process for the production of a packed product, a process for the production of an at least partly coated object, and uses of the esters according to the invention as an additive in various compositions.
