Sales Zachary S, Mani Neelakandha S
Johnson & Johnson Pharmaceutical Research and Development, L.L.C., 3210 Merryfield Row, San Diego, California 92121, USA.
J Org Chem. 2009 Jan 16;74(2):891-4. doi: 10.1021/jo802193z.
A novel intramolecular 1,3-dipolar cycloaddition strategy for a rapid entry into benzofuropyrazoles is described. In a three-step sequence, (E)-2-(1,2-dichlorovinyloxy)aryldiazomethanes were generated in situ from the corresponding salicylaldehydes. Intramolecular cycloaddition followed by dehydrohalogenation garnered 3-chlorobenzofuropyrazoles in excellent yields. By careful choice of solvent, base, and reaction conditions, the entire sequence can be carried out in a one-pot procedure.
描述了一种用于快速合成苯并呋喃并吡唑的新型分子内1,3-偶极环加成策略。通过三步反应序列，由相应的水杨醛原位生成（E）-2-（1,2-二氯乙烯氧基）芳基重氮甲烷。分子内环加成后进行脱卤化氢反应，以优异的产率得到3-氯苯并呋喃并吡唑。通过仔细选择溶剂、碱和反应条件，整个反应序列可以在一锅法中进行。
