Pyrazolo[4′,3′:5,6]pyrano[2,3-<i>b</i>]quinoxalin-4(1<i>H</i>)-one: Synthesis and characterization of a novel tetracyclic ring system
作者:Gernot A. Eller、Barbara Datterl、Wolfgang Holzer
DOI:10.1002/jhet.5570440526
日期:2007.9
Derivatives of the hitherto unknown ring system, pyrazolo[4′,3′:5,6]pyrano[2,3-b]quinoxalin-4(1H)-one, are synthesized in one step from the corresponding 1-substuituted or 1,3-disubstituted 2-pyrazolin-5-ones and 3-chloroquinoxaline-2-carbonyl chloride using calcium hydroxide in boiling 1,4-dioxane. The parent system carrying no substituent in positions 1 and 3 is obtained upon treatment of the 1-PMB
迄今未知的环系统的衍生物吡唑并[4',3':5,6]吡喃并[2,3 - b ]喹喔啉-4(1 H)-一是从相应的1-取代基或-取代基合成的。在沸腾的1,4-二恶烷中使用氢氧化钙制备1,3-二取代的2-吡唑啉-5-酮和3-氯喹喔啉-2-羰基氯。通过用三氟乙酸处理1-PMB(对甲氧基苄基)保护的同类物,获得在位置1和3上不具有取代基的母体系统。报告了详细的NMR光谱研究,包括获得的四环的所有1 H,13 C和15 N共振的明确化学位移分配。