Formation of methylanisole in the photolysis of chlorotoluene in methanol

Photolyses of p-, m- and o-chlorotoluene in methanol gave formation quantum yields of methylanisoles of the order of 10⁻², which are substantially smaller than that for chlorobenzene. The values for the para and ortho isomers are smaller than that for the metal isomer. This result can be explained in terms of the effect of the methyl substituent, which induces negative charges at the ortho and para positions. The effect of biacetyl addition was also examined and the results indicated that the triplet route is significant, as in the case of chlorobenzene. However, about half the methylanisole was formed without any dependence on the biacetyl concentration, indicating the presence of an intermediate state with a very short lifetime.