PHOTOTHERMAL SIDE-CHAIN BROMINATION OF METHYLBENZENES, DIMETHYLBENZENES, AND TRIMETHYLBENZENES WITH N-BROMOSUCCINIMIDE

Tri- and dibromination of methyl-, dimethyl-, and trimethylbenzenes wi th N-bromosuccinimide were accomplished by photothermal reaction with a tungsten lamp in carbon tetrachloride or benzene. (Dibromomethyl)are nes and (tribromomethyl) derivatives were produced depending upon a so lvent used and a substituent on the benzene ring. In the bromination o f methylbenzenes without a substituent on the ortho-position, (tribrom omethyl) benzenes were formed. On the other hand, ortho-substituted me thylbenzenes gave (dibromomethyl)benzenes. alpha,beta-Dibromo-1,2-diar ylstilbenes were formed via the debrominative carbon-carbon coupling r eaction of (tribromomethyl) benzenes upon irradiation with a tungsten lamp.