A four-component synthesis of novel spiro[pyrazoloquinoline-oxindoles] under solvent-free conditions
摘要:
A domino reaction for the rapid and diverse synthesis of spiro[1H-pyrazolo[3,4-b]benzo[h]dihydroquinolin-4,3-indolin-2-ones] is reported. The synthesis represents a thermodynamically-favored four-component reaction between phenylhydrazine, isatins, naphthylamines, and 3-ketoesters giving the novel products in excellent yields under solvent-free conditions. Similar applications of anilines in place of naphthylamines have not led to formation of the expected 4-substituted pyrazolo[3,4-b]quinoline derivatives. The difference was ascribed to lower aromatic character of naphthylamines, with respect to anilines, which enables them to act easier as enamines in reaction with the postulated intermediates formed from condensation of isatins and the in situ generated pyrazolones. Surprisingly, 6-aminouracils in despite of their known enamine properties did not participate in reaction with isatins and pyrazolones, the merit of naphthylamines for this synthesis seems to be met by the favorable balance of their N- and C-nucleophilicity. (C) 2014 Elsevier Ltd. All rights reserved.
Preparation of spirooxindoles catalyzed by nano-Co3S4 under microwave irradiations
作者:Sheida Khojasteh-Khosro、Hossein Shahbazi-Alavi
DOI:10.1177/1747519819841791
日期:2019.3
efficient and rapid method is used for the synthesis of 10-methyl-8H-spiro[benzo[5,6]chromeno[2,3-c]pyrazole-11,3′-indol]-2′(1′H)-one and 8-methyl-10-phenyl-10,11-dihydrospiro[pyrazolo[3,4-b]benzo[h]quinolin-7,3′-indol]-2′(1′H)-one by a four-component reactions of phenylhydrazine or hydrazine hydrate, isatins, ketoesters, and naphthylamine or 2-naphthol using nano-Co3S4 undermicrowaveirradiation.