Photolysis of Naphthyl and Quinolyl Azides: A Practicable Synthesis of Naphthyl and Quinolylo-Diamines

Flash Photolysis of the Naphthyl Azides with UV−Vis and IR Detection of Intermediates

“…The observed reaction of azirine 7 with DEA is not particularly fast, but trapping by DEA is still a major process because 7 has a long lifetime (150 μs) in the absence of amine trap. This is consistent with the reported high yields of adducts formed upon photolysis of 2-naphthyl azide 2 with the presence of secondary amine. ,, A DEA adduct is inefficiently formed upon photolysis of 1-naphthyl azide 1 at ambient temperature because of the shorter lifetime of its naphthazirine derivative ( 4 ), which converts to triplet 1-naphthylnitrene 3t in two steps, and consequently renders this azirine unavailable to nucleophiles.…”

“…The products obtained upon pyrolysis and photolysis of the naphthyl azides were first reported in the 1970s and 1980s. − In 1974, the Suschitzky group discovered that the thermal decomposition of 1- and 2-naphthyl azides ( 1 and 2 ) in bromobenzene yields significant amount of dibenzo[ a , h ]phenazine. The photolytic decomposition of 2-naphthyl azide 2 in diethylamine (DEA) leads to a diamine product, but photolysis of 1-naphthyl azide 1 in DEA produces mostly azonaphthalene and aminonaphthalene in low yields 8 and a very low yield of diamine adduct .…”

“…In 1975, Carroll et al found that the yield of diamine product is sensitive to the photolysis time. A drastic reduction in photolysis time leads to a much-improved yield of the diamine …”

Kinetics, Spectroscopy, and Computational Chemistry of Arylnitrenes

“…Much effort has been devoted to the study of the photochemistry of 1- and 2-naphthyl azides ( 38 and 39 ). The products obtained upon pyrolysis and photolysis of the naphthyl azides were reported in the 1970s. ,,,− In 1974, the Suschitzky group 80 discovered that the thermal decomposition of 38 and 39 in bromobenzene yields a significant amount of dibenzo[a,h]phenazine (Scheme 10). The photolytic decomposition of 2-naphthyl azide 39 in diethylamine (DEA) leads to a diamine product, but photolysis of 1-naphthyl azide 38 in DEA produces mostly azonaphthalene and aminonaphthalene in low yields 80 along with a very low yield of diamine adduct …”

“…In 1975, Carroll et al found that the yield of diamine product is sensitive to the photolysis time . A drastic reduction in photolysis time leads to a much-improved yield of the diamine.…”