Method for reprocessing reaction mixtures containing diaryl carbonate

A process for the work up of a reaction mixture obtained from the preparation of diaryl carbonate by direct carbonylation of aromatic hydroxy compounds, the carbonylation entailing a reaction step, comprising (i) obtaining a reaction mixture that contains diaryl carbonate, aromatic hydroxy compound, water, base and quaternary salt, (ii) separating said mixture in a distillation apparatus having only one theoretical separation stage at pressures from 1 to 100 mbar and at temperatures from 80 to 160° C. into a bottom product and top product, said bottom product containing diaryl carbonate, aromatic hydroxy compound, base and quaternary salt and said top product containing diaryl carbonate, aromatic hydroxy compound and water, (iii) recycling said bottom product without further work up to the reaction step of said direct carbonylation and (iv) working up the top product.