Dimethyl 4-dimethylaminophenyl 4-methoxyphenyl

The photo-oxidation of the aryl-substituted cycloheptatrienes 7-(/ -methoxy-phenyl)cycloheptatriene and 7-, 1- and 3-(/ -dimethylaminophenyl)cycloheptatrienes to the corresponding radical cations in de-aerated acetonitrile solution was accomplished by electron transfer to the electronically excited acceptors 9,10-dicyanoanthracene, iV-methylquinolinium perchlorate, iV-methylacridinium perchlorate and l,T-dimethyl-4,4-bipyridinium dichloride. In the case of l- p-methoxyphenyl)cycloheptatriene (62), deprotonation of the radical cation occurs successfully, compared with back electron transfer, to give a cycloheptatrienyl radical (63) which undergoes a self-reaction forming a bitropyl. If the photooxidation is done in air-saturated acetonitrile solution containing HBF4 and one of the acceptors, the tropylium cation is formed. Back electron transfer dominates in the / -dimethylaminocycloheptatrienes and the formation of the cycloheptatrienyl radical is prevented. 

Dimethylaminophenyl 4-Methoxyphenyl Tellurium Bromide Succinimide1 1.42 g (4 mmol) of 4-dimethyl-aminophenyl 4-methoxyphenyl tellurium are dissolved in 50 ml of benzene and 0.72 g (4 mmol) of A -bromosuccinimidc dissolved in 10 ml of benzene are added. The mixture is stirred for 3 h, the yellow crystalline precipitate is filtered off, washed with benzene, and dried under reduced pressure yield 2.1 g (100%) m.p. 160°... 

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