抄録
9-Phenylthioxanthylium perchlorate (I) reacts under an N2 stream with C6H5MgBr and CH2MgI and gives 9, 9-diphenylthioxanthene (II) and 9-methyl-6-phenylthioxanthene (IV), respectively, as main products. In the presence of air, 9-phenylthioxanthyl peroxide (III) is formed as a by-product by the reaction of I with C6H5MgBr. The mechanism of these reactions was clarified by the studies by the ESR technique. The spectrum of 9-phenylthioxanthyl radical (VI), which was a reaction intermediate, was analyzed by the McLachlan SCF-MO computation. The electron spin resonance spectrum of VI was alos observed by the formation of 9, 10-diphenyl-10-thiaanthracene (V) by the reaction of I with C6H5Li. In order to examine the mechanism of formation of thioxanthenes and thiaanthracenes, the chemical reactivity of VI was studied. VI reacted with iodine, air, and the solvents such as ether and THF to give XIII, III, and XII, respectively. It did not react with organometallic reagents such as Grignard reagents and C6H5Li but reacted with ether to give XII only. However, it gave IV and V by the reaction with CH3MgI and C6H5Li, respectively, in the presence of CoBr2. These experimental results show that the radical mechanism considierably contributes to the reactions between I and organometallic reagents.
