One pot four-component reaction for the efficient synthesis of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole]-3′-carboxylate derivatives
作者:Suman Pal、Md. Nasim Khan、Shaik Karamthulla、Sk Jahir Abbas、Lokman H. Choudhury
DOI:10.1016/j.tetlet.2013.07.117
日期:2013.10
to synthesize various spiro[indoline-3,4′-pyrano[2,3-c]pyrazole]-3′-carboxylate derivatives from the four-componentreaction of isatin, malononitrile, hydrazine derivatives and dialkyl acetylenedicarboxylates. In this process two C–C bonds, two C–N bonds and one C–O bond have formed in one pot. The notable features of this protocol are simple and environmentally benign reaction condition, easy isolation
已经开发了一种新颖的一锅法,该方法可以从靛红,丙二腈,肼衍生物和四价胺的四组分反应合成各种螺[吲哚啉-3,4'-吡喃并[2,3- c ]吡唑] -3'-羧酸酯衍生物。乙炔二羧酸二烷基酯。在此过程中,在一个罐中形成了两个C–C键,两个C–N键和一个C–O键。该方案的显着特征是简单且对环境无害的反应条件,易于分离的产物,适用于各种现成的起始原料和良好的收率。
Green access to novel spiro pyranopyrazole derivatives
A catalyst-free multicomponent reaction (MCR) capable of affording a wide range of novel spiro pyranopyrazole derivatives from pyrazolone in situ formed from acetylenic esters with hydrazine hydrate at room temperature with isatin and malononitrile is reported. A plausible mechanism is suggested. Catalyst-free conditions along with green solvent system make the process ecofriendly as well as economical. Simple reaction conditions and easy work-up procedure that resulted into simple isolation and purification of products by non-chromatographic methods, that is, by simple recrystallization from methanol as well as novelty are the significant advantages of the present protocol. (C) 2013 Elsevier Ltd. All rights reserved.