Preparative-scale synthesis of amino coumarins through new sequential nitration and reduction protocol
作者:Hemchandra K. Chaudhari、Akshata Pahelkar、Balaram S. Takale
DOI:10.1016/j.tetlet.2017.09.040
日期:2017.10
approach for nitration (for example HNO3/H2SO4) and for reduction (for example Zn/HCl), we hypothesized that sensitive heterocycles such as coumarins could not withstand with those hard conditions. Hence, while studying this reaction sequence to prepare amino coumarins (which is our ongoing project to synthesize antitubercular coumarin agents), we came across mild and greener reagent for nitration using calcium
与传统的用于硝化(例如HNO 3 / H 2 SO 4)和用于还原(例如Zn / HCl)的有害方法相反,我们假设敏感的杂环(如香豆素)无法在那些困难的条件下承受。因此,在研究此反应顺序以制备氨基香豆素(这是我们正在进行的合成抗结核香豆素试剂的正在进行的项目)时,我们遇到了使用硝酸钙(Ca(NO 3)2 ·4H 2 O;硝酸钙)进行硝化的温和绿色试剂。),并使用d-葡萄糖还原。本文讨论了这两种温和的,化学选择性的,高产率的方法。