Study on Preparation of Benzaldehyde from Benzyl Chloride

Using benzyl chloride and chlorine as starting materials, benzal chloride is prepared through photo-chlorination in loop reactor. The refined product with high purity is obtained by vacuum distillation of crude benzal chloride. Then highly purified benzaldehyde can be obtained through hydrolysis in the medium consisting of hydrochloric acid and water, under temperature at the range of 90～110℃ in presence of phase transfer catalyst. Based on investigation of influence of reaction temperature and chlorine flow on the conversion rate of chlorinating benzyl chloride and studies about temperature, selection of medium and its dosage which are influencing on hydrolysis the optimal reaction conditions are determined.