The photochemistry of three types of 2-(alklylcarbamoyl)quinolines was studied. The illumination of 2-(diethylcarbamoyl)quinolines (1a, 1b, and 1c) afforded 2-(2-ethylaminopropionyl)quinolines (3a, 3b, and 3c) with a small amount of five-membered cyclic products, 1H-pyrrolo[3,4-b]quinolin-3(2H)-ones (4a, 4b, and 4c), both of which were formed via Type-II hydrogen-atom abstraction from the T1 state. 2-(Ethylcarbamoyl)quinoline (1d) did not undertake any photochemical change. The photochemical inactivity of 1d could be attributed to the unfavorable orientation of its carbamoyl substituent for intramolecular hydrogen-atom abstraction by a ring nitrogen. The illumination of 2-(alkylcarbamoyl)-3-methyl quinolines (2a and 2b) afforded 2-(N-acetyl-N-alkylcarbamoyl)-3-methyl quinolines (5a and 5b), which were suggested to be formed by the atmospheric oxidation of an unstable photoproduct formed via the S1 state.
研究了三种 2-(烷基
氨基甲酰基)
喹啉的光
化学过程。照射 2-(
二乙基氨基甲酰基)
喹啉(1a、1b 和 1c)可得到 2-(2-乙基
氨基丙酰基)
喹啉(3a、3b 和 3c)和少量五元环状产物 1H-
吡咯并[3,4-b]
喹啉-3(2H)-酮(4a、4b 和 4c),这两种产物都是通过从 T1 态抽取 II 型氢原子形成的。2-(乙基
氨基甲酰基)
喹啉(1d)没有发生任何光
化学变化。1d 不具有光
化学活性的原因可能是其
氨基甲酰基的取向不利于环氮分子内氢原子的抽取。照亮 2-(烷基
氨基甲酰基)-
3-甲基喹啉(2a 和 2b)可得到 2-(N-乙酰基-N-烷基
氨基甲酰基)-
3-甲基喹啉(5a 和 5b),这两种
喹啉可能是通过 S1 态形成的不稳定光反应产物在大气中氧化形成的。