Preparation of tri-o-tolyl phosphite_Industrial additives

Overview^[1-2]

Tri-o-tolyl phosphite belongs to the triaryl phosphite compounds. Triaryl phosphite is an important chemical raw material. It is mainly used as an antioxidant and stabilizer for polymers and as a chelate in various polyethylene products. mixture is also an important organophosphorus ligand. Tri-o-tolyl phosphite can be used as a ligand for metal complexes and as a plasticizer.

Preparation^[1-2]

Method 1,

1) Add o-cresol to the one-step reaction kettle, then add phosphorus trichloride dropwise, react at room temperature for 5 hours, and remove hydrogen chloride under negative pressure during the reaction; the one-step reaction kettle is an enamel jacketed kettle;

2) Transfer the reaction material obtained in step 1) into a two-step reaction kettle and react at 150°C for 3 hours. During the reaction, nitrogen is blown to remove hydrogen chloride to generate a product containing tri-o-tolyl phosphite; as described The two-step reaction kettle is a stainless steel jacketed kettle; after the reaction, excess o-cresol and intermediates are removed by vacuum distillation to obtain a product with a purity of more than 98% and a yield of 88%.

Method 2,

Put the reaction bottle into the oil bath and secure it. Weigh 324.42 grams of o-cresol. Since the freezing point of o-cresol is 30.9°C, first heat and melt the o-cresol into a liquid and then add it to the reaction bottle. Weigh 137.33 grams of phosphorus trichloride and add it to the constant pressure dropping funnel. Then immediately Cap the rubber stopper to seal the conductive carbon black at the top of the constant pressure dropping funnel, then install the funnel on the reaction bottle and fix it. After the condenser tube and thermometer are installed, slowly open the valve of the constant pressure dropping funnel and start stirring. After 40 minutes, the dripping of phosphorus trichloride is completed. Stir at room temperature for 16 hours. The reaction pressure is 770mmHg. The temperature rises to 70°C and is maintained for 1 hour. Then the temperature was raised to 200°C and fully refluxed for 4 hours. Negative pressure distillation, the distillation temperature is 230°C, the distillation pressure is 1mmHg, the distillation time is 2h, the gas phase is 193°C, and the pressure is 1mmHg. 186 grams of fractions are collected. Chromatographic analysis shows that the tri-o-tolyl phosphite component accounts for 90.03% of the chromatographic peak area. .