Background and overview[1]
Phenyl phosphate dichloride is used as an intermediate in organic synthesis and as a dehydrating agent in the oxidation reaction of dimethyl sulfoxide. It is widely used in the synthesis of chemical intermediates; there has been no synthesis report in China so far.
Structure
Preparation[1]
1. Synthesis process
In a 500mL three-neck flask, add 359g (2.3mol) of phosphorus oxychloride, heat it in an oil bath, and the liquid temperature rises to 80-90°C. During this process, the system emits HCl white smoke. Maintain the temperature until no white smoke is released, then the equipment is dried, that is, 7.5g (0.068mol) of quaternary ammonium salt catalyst is added to maintain the liquid phase temperature at 80-90°C. Phenol should be heated and dissolved in advance. After adding 150g (1.56mol) of dissolved phenol into the dropping funnel, add phenol dropwise within the liquid temperature range of 80-90°C in the three-neck flask. The dropping speed should be uniform, exhaust gas should be released, and the temperature It cannot be too high, otherwise side effects will occur. After adding the phenol dropwise to the Kao antistatic agent, keep the reaction at 80-92℃ until no white smoke is released in the tail gas, and then raise the temperature to 92-120℃. The reaction end point is when there is very little white smoke in the tail gas; the tail gas should be introduced into the water flow pump for absorption. System, the total reaction time is about 4 hours.
2. Distillation and cutting process
(1) Atmospheric pressure distillation is heated under normal pressure to evaporate excess phosphorus oxychloride. When the gas phase temperature rises to 120°C, normal pressure distillation will stop if no fraction is evaporated.
(2) Distillation conditions before vacuum distillation: gas phase temperature: 140°C, liquid phase temperature: 145-150°C, vacuum degree: 0-93310Pa The product collection conditions are gas phase Temperature: 140-141℃, liquid phase temperature: 146-150℃, vacuum degree: 9464.3Pa, the collected product is high-content phenyl phosphate dichloride, weight: about 250g, content ≥96%, yield about 73% .
