Oxidation of 6- and 8-methylquinolines upon UV-illumination in the presence of a powder of TiO2 photocatalyst.
Selective transformation of the methyl group into a formyl group in methylquinolines is of great interest because formation of the corresponding aldehydes is either very expensive or unknown. We report here results concerning the photo-oxidation of 6- and 8-methylquinolines (6-MQ and 8-MQ) suspended with TiO2 powder in oxygenated acetonitrile. The analytical study of the products generated from the TiO2-photoassisted oxidation of 6-MQ and 8-MQ in oxygenated acetonitrile suspensions indicated that in both cases, for a UV-illumination period of < 24 h, the corresponding formyl derivatives quinoline-6- and -8-carbaldehydes are detected as practically the sole products. Analysis of further photogenerated oxidation products enabled mechanistic delineation of the course of the semiconductor-mediated reaction.
Navío
J A
JA
Instituto de Ciencia de Materiales de Sevilla, Centro Mixto CSIC-Universidad de Sevilla and Dpto. de Química Inorgánica, Universidad de Sevilla, Avda. Américo Vespucio, s/n, 41092-Sevilla, Spain. navio@cica.es
Garcia-Gómez
M
M
Pradera
M A
MA
Fuentes
J
J