yield is thought to be the combination of high temperature and low to medium pressure these two conditions result in low concentrations of dmc in the reactor mixture dmc is a low boiling component and high concentrations of pmc so the disproportionation reaction of pmc to dpc and dmc is shifted towards the dpc side the present invention is further illustrated in a number of working examples summarized in table 1 pmc yield moles pmc generated per mole phenol in feed dpc yield moles dpc generated times 2 per mole phenol in feed pmc dpc yield pmc yield plus dpc yield anisole selectivity moles anisole generated per mole phenol converted a pilot distillation column stainless steel as shown in fig2 was equipped with 40 perforated plates the plate diameters were 50 mm for the bottom 20 trays and 40 mm for the top 20 trays the total height of the column was 3 4 m with a plate to plate distance of 50 mm for the bottom 20 trays and 40 mm for the top 20 trays the holdup of the bottom 20 trays was 471 ml of liquid the holdup of the bottom compartment of the column was 460 ml heat was supplied at the bottom of the column and to the bottom 20 trays of the column by means of electric heating mantles the phenol feed 548 g h and catalyst feed titanium tetraphenolate 40 3 wt dissolved in a.