Industrial & Engineering Chemistry Research, Vol.59, No.2, 1025-1029, 2020
Ton-Scale Production of 1,4-Bis(dichloromethyl)-2,5-dichlorobenzene via Unexpected Controllable Chlorination of 1,4-Dichloro-2,5-dimethylbenzene
Herein, we report a novel technique for the production of 1,4-bis(dichloromethyl)-2,5-dichlorobenzene, which was once difficult to synthesize for the complex reaction selectivity issues. It was found that by adding AIBN as the free-radical initiator slowly and performing the reaction under mild conditions, the product selectivity could be well controlled to produce 1,4-bis(dichloromethyl)-2,5-dichlorobenzene as the major product. The reaction could be successfully applied in ton-scale production to afford 1,4-bis(dichloromethyl)-2,5-dichlorobenzene in 73% yield. As a method that can use p-xylene as the cheap and abundant starting material and chlorine gas as the efficient chlorination reagent, this technique is of low cost for real industrial production. Moreover, as an example of the efficient and precise transfer of chlorine, it may attract broad interest and provide references for further development of new chlorization techniques.