新型光敏催化剂用于甲苯侧链氯化反应

Side-Chain Chlorination of Toluene with New Photosensitive Catalyst

为提高目的产物收率及选择性,缩短反应时间,将新型光敏催化剂BMMB用于甲苯侧链的氯化反应,制取三氯甲苯.这种光敏催化剂有较强的反应活性和贮存稳定性,对设备无腐蚀作用.采用催化剂2,2' 偶氮二异丁腈、过氧化苯甲酰或三氯化磷时可知:2,2' 偶氮二异丁腈在反应中易消耗掉,需在反应中不断添加;过氧化苯甲酰储存和运输不稳定;三氯化磷沸点低,易分解失活,会阻碍制苯甲酰氯的水解反应,增加产物中磷残存量,且对设备有腐蚀作用.新型光敏催化剂BMMB没有上述缺点.含0.5%BMMB的甲苯在蓝光照射下于110～120℃氯化8h,三氯甲苯收率为95.5%～96.5%,优于2,2' 偶氮二异丁腈、过氧化苯甲酰和三氯化磷.

In order to improve the selectivity and the yield of product, shorten the reation time, a new photosensitive catalyst BMMB with high reactive activity, stability of storage and non-corrosiveness has been used for the side-chain chlorination of toluene to produce benzotrichloride. Previously, catalyst, such as 2,2′-azo-bis-iso-butyronitrile, benzoyl peroxide and phosphorus trichloride, was used. But 2,2′-azo-bis-iso-butyronitrile decomposes easily, needing continuous addition in the reaction procedure; benzoyl peroxide is unstable in storage and transport, and phosphorus trichloride with low boiling point easily decomposes to loss activity. Thus the hydrolysis reaction to produce bezoyl chloride was inhibited; the content of phosphorus element in the product was increased and the equipment was corroded. The new photosensitive catalyst BMMB has no such defects as mentioned above. Therefore, when toluene containing 0.5% BMMB is chlorinated 8 hours at 110—120 ℃ under the radiation of blue light, the yield of benzotrichloride is 95.5%—96.5%,which is better than 2,2′-azo-bis-iso-butyronitrile, benzoyl peroxide and phosphorus trichloride.