PROCESS FOR THE PREPARATION OF TRIS-(2,4-DITERT-BUTYLPHENYL)PHOSPHITE

A process far the preparation of tris-(2,4-ditert-butylphenyl) phosphate from 2,4-ditert-butylphenol and phosphorus trichloride in the presence of catalysts, which comprises carrying out the reaction in an at least three-stage process in which the 2,4-ditert-butylphenol and 40 - 100 % of the catalyst are combined in a preliminary stage and are brought together with the phosphorus trichloride in a first stage, these being allowed to react under normal pressure and at temperatures of 55 to 70.degree.C for a dwell time of 15 to 40 minutes, the reaction mixture is then reacted in a second stage under normal pressure and at temperatures of over 140.degree.C, remaining amounts of catalyst being added to the first and/or second reaction stage, the reaction mixture is then kept under reduced pressure at temperatures of at least 186.degree.C in a third reaction stage, and the tris-(2,4-ditert-butylphenyl) phosphate is then isolated from the reaction mixture, the process being carried out in the absence of solvents.