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non-demanding Grignard and organolithium reagents displace the methoxy-group in tetrachloro-4methoxy-pyridine, with the formation of 4-alkyl-or 4-aryl-tetrachloropyridines. t-Butyl-lithium forms trichloro-4methoxy-3-pyridyl-lithium, which decomposes in the presence of furan with the formation of 2,3-dichloro-5,8dihydro-4-methoxy-5.8-epoxyquinoline.

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Tetrachlorobenzyne and tetrafluorobenzyne react with styrene to yield predominantly or exclusively 1,2,3,4-tetrahalogeno-9,lO-di hydrophenanthrenes or 1.2.3.4-tetrahalogenophenanthrenes in good yield. Similar reactions are reported in which the arynes were generated in the presence of a-methyl-, trans-p-methyl-, 2-methyl-, 3-methyl-, 4-methyl-, and 2,4-dimethyl-styrene. Reactions were also carried out with trans-stilbene, 1 ,I -diphenylethylene, 1 -phenylcyclohexene, and 1 -vinylnaphthalene. The mechanism of formation of 1.2.3.4-tetrafluoro-9.1 O-dihydrophenanthrene has been studied by use of suitably deuteriated compounds. A discussion of the mechanism of formation of 1,2,3,4-tetrafluorophenanthrene, and of 9,1O-dihydro-9-phenylphenanthrene in the reaction of benzyne with styrene, is based on reactions with deuteriated styrenes.SEVERAL papers describing reactions of benzyne with substituted styrenes to give phenanthrene derivatives in low yield have appeared.2 However, no well defined product had been obtained with styrene i t ~e l f . ~ In view of the high yields obtained in cycloaddition reactions of tetrahalogenobenzynes,4 we have investigated the reactions of tetrachlorobenzyne and tetrafluorobenzyne with styrene and some derivatives. During these studies preliminary communications appeared which describe reactions of benzyne with styrene and with a-methylstyrene.6 The results of reactions of tetrafluorobenzyne with styrene have also been reported by