Substituted benzopinacols and their preparation

Abstract From the Canadian patent

Benzopinacols represented by the formula: wherein, R1 is hydrogen, alkyl or aryl; R2 and R6 independently are selected from the group consisting of hydrogen, halogen or trifluoromethyl; R3 and R5 independently are selected from the group consisting Or hydrogen, halogen and alkyl or when, taken together with R4, represent a tetramethylene group; and, R4 is selected from the group consisting of hydrogen halogen, alkyl, alkoxy and phenoxy;, with the proviso that when both of the ortho positions of the phenyl groups at which R2 and R6 are attached are substituted, the substituent is fluorine. These and other benzopinacol compounds can be prepared by an improved process comprising irradiating a …