MAOS of Quinoxalines, Conjugated Pyrazolylquinoxalines and Fused Pyrazoloquinoxalines from <scp>l</scp>‐Ascorbic and <scp>d</scp>‐Isoascorbic Acid
作者:El Sayed H. El Ashry、Kamal F. Atta、Salah Aboul‐Ela、Razika Beldi
DOI:10.1080/07328300701252359
日期:2007.3.1
Microwave‐assisted organic synthesis (MAOS) has been used to accelerate the conversion of L‐ascorbic acid (1) and D‐isoascorbic acid (2) to the title heterocycles by conversion to 3‐(L‐threo‐ or D‐erythro‐glycerol‐1‐yl)quinoxaline‐2‐carboxylic acid o‐aminoanilides (7 and 8), which were transformed to lactones 9 and 10, respectively, under acidic condition. The acetylation of compounds 9 and 10 afforded
微波辅助有机合成(MAOS)已用于通过将L-抗坏血酸(1)和D-异抗坏血酸(2)转化为3-(L-苏-或D-赤藓基-)来加速标题杂环的转化甘油-1-基)喹喔啉-2-羧酸邻氨基苯胺(7和8),在酸性条件下分别转化为内酯9和10。化合物9和10的乙酰化可生成3-(L-苏-或D-赤型-2,3-二-O-乙酰基-甘油-1-基)喹喔啉-2-羧酸-γ-内酯(11和12) 。用苯肼处理10得到酰肼13。制备了3- [1- [苯基肼基-L-苏--2,3,4-三羟基丁基] -1H-喹喔啉-2--1(14)和其D-赤型-模拟物15。从1和2开始。随后的环化反应分别得到吡唑基喹喔啉16和17以及吡唑并[3,4-b]喹喔啉26和27。研究了16和17的烯丙基化和环氧丙基化的区域选择性,可以用半经验AM1方法解释。降解26或27可得到1-苯基吡唑并[3,4-b]喹喔啉-3-羧甲醛(28)。降解14或15可获得醛29。结