To a 500-mL four-necked flask equipped with a stirrer, reflux condenser and thermometer were added 19 g (0.1 mol) of trisodium salt of cyanuric acid, 71 g (0.33 mol) of 2-tert-butyl-3-chloromethyl-4,6-dimethylphenol, 200 mL of N,N-dimethylformamide, and 1 g of phase transfer catalyst. The reaction mixture was heated to 120°C and stirred for 14 hours under continuous nitrogen protection. Upon completion of the reaction, the mixture was cooled to 50-60°C and filtered. The filtrate was distilled at 0.005-0.15 MPa pressure to remove N,N-dimethylformamide. To the residue, 200 mL of toluene and 100 mL of water were added and stirred until all materials were completely dissolved, then left to partition and separate the aqueous phase. The organic phase was distilled to remove the remaining water and about 160 mL of toluene. 150 ml of methanol was added slowly, stirred and refluxed until the material was completely dissolved. 5 g of activated charcoal was added for decolorization, and after hot filtration, the product was cooled and crystallized, filtered, and washed to give 54.6 g of dry 1,3,5-tris(4-(tert-butyl)-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazinane-2,4,6-trione with a melting point of 157-160 °C and a purity of 98.3%. The product was characterized by infrared spectroscopy.
