Preparation method of photoinitiator phenyl bis(2,4,6-trimethylbenzoyl)-phosphine oxide

The invention discloses a preparation method of a photoinitiator phenyl bis(2,4,6-trimethylbenzoyl)-phosphine oxide, comprising the steps of enabling diethyl benzylphosphonate and an excessive vitride solution to react in argon under the temperature of 60-70 DEG C, so as to generate phenyl phosphine, enabling the phenyl phosphine and 2,4,6-trimethylbenzoyl chloride to react, so as to obtain a methylbenzene solution of diphenyl(2,4,6-trimethylbenzoyl)phosphine, and oxidizing the diphenyl(2,4,6-trimethylbenzoyl)phosphine into 2 phenyl bis(2,4,6-trimethylbenzoyl)-phosphine oxide by hydrogen peroxide without separating. According to the process, dangerous metal sodium or potassium is not used, the process is advanced, the operation is simple and safe, the product yield is high, the quality is good, and large-scale production is easy.