摘要 证明了二甲基尿素和L-酒石酸作为深共熔溶剂(DES)在合成2-(甲基氨基)-3-硝基螺并[ N ] -N-甲基-3-硝基-4 H -chromen -2中的应用。 -胺通过取代的靛红/吡唑醛,亲核试剂和(E)-N-甲基-1-(甲硫基)-2-硝基乙胺的反应而形成。系统研究表明,在80°C下以2:1的比例存在的二甲基脲和L-酒石酸适合在较短的反应时间(45分钟)内以良好的收率获得所需的产物。将该方法扩展到以水为反应介质,并在1小时内获得了良好的产物收率。
Indium Trichloride Catalysed Domino Reactions of Isatin: A Facile Access to the Synthesis of Spiro(indoline-3,4′-pyrano[2,3-c]pyrazol)-2-one Derivatives
A versatile high-yielding indium trichloride mediated one-pot regioselective synthesis of spiroxindoles via domino one-pot, three-component reaction of isatins, pyrazoles, and (E-)-N-methyl-1-(methylthio)-2-nitroethenamine is described. This reaction presumably occurs via domino Knoevenagel condensation-Michael addition-intramolecular O-cyclization sequence. The salient features of the methodology are its clean reaction conditions, the eco-friendly medium, low cost, easy isolation, and excellent yields without column chromatographic purification.