I. Ono, N. Hata
Aug 1, 1987
Citations
0
Influential Citations
9
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The photochemical reactions of the quinoline derivatives substituted by an ethoxycarbonyl group at the 2-, 3-, and 4-positions of a quinoline nucleus have been investigated in several alcohols and cyclohexane. Irradiation of ethyl 4-quinolinecarboxylate (1) yielded ethyl 2-hydroxyalkyl-4-quinolinecarboxylates (4a–c) in alcohols and ethyl 2-cyclohexyl-4-quinolinecarboxylate (4d) in cyclohexane in a good yield, respectively. The photochemical reactions of ethyl 3-quinolinecarboxylate (2) showed remarkable solvent dependency. Irradiation in methanol and cyclohexane afforded a solvent-additive product, ethyl 4-hydroxymethyl-1,4-dihydro-3-quinolinecarboxylate (5a) and ethyl 4-cyclohexyl-1,4-dihydro-3-quinolinecarboxylate (5b), while such photoaddition of the solvent did not proceed in ethanol and 2-propanol but instead ethyl 1,4-dihydro-3-quinolinecarboxylate (6) and dimeric compounds were formed, both of which were unstable and finally reverted to 2 at room temperature in air. In the case of ethyl 2-quinoline...