Abstract-Long range 13C-IH coupling constants are reported for a number of methylquinoline derivatives. The results have been compared with those observed in the pyridine series and correlated with lH--'H coupling constants.

The reactions between hexafluorobenzene and a series of diaroyl peroxides have been shown to give 2,3,4,5,6pentafluorobiphenyl and appropriately substituted derivatives. The significance of the yields of the biaryls obtained and the nature of the other reaction products are discussed, and a mechanism for the reaction is suggested tentatively.

The products formed during the thermal rearrangements of 1 -alkylpyridinium iodides a t 300" in sealed tubes (Ladenburg rearrangement) have been shown to consist of the hydriodides of the original bases, their alkylated derivatives, and binuclear bases including bipyridyls and dipyridylalkanes, together with hydrocarbons derived from the 1 -alkyl substituents by gain or loss of hydrogen atoms. The pronounced directing influence towards a-and y-positions of the pyridine ring associated with this reaction has been confirmed. On the basis of these and other results, a mechanism is proposed which involves the homolytic dissociation of the nitrogen-alkyl bond, and in the case of the iodides also depends on their existence partly as charge-transfer complexes. * H. S. Mosher, ' Heterocyclic Compounds,' ed. R. C. Elder-9 E, N. Shaw, ' The Chemistry of Heterocyclic, Compounds,' (Part 2), ed.

8 from equation (1) are more consistent with values of 8 determined by the two methods above except when 8 is small, when equation (2) gives the better correlation; the equations themselves show the greatest divergence when 8 is 45".Frolen and Goodman14 have shown that for a series(2)C O S ~ e =

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