Ultrasound promoted, cerium ammonium nitrate catalyzed sustainable synthesis of spiro[indoline3,4'-pyrano[2,3-c]pyrazole] derivatives (4a-l) is reported herein. The synthesized compounds were screened for their antioxidant activities as free radical scavenging effect on diphenylpicryl hydrazine (DPPH center dot), 2,2'-azino-bis(3-ethylbenzthiazoline- 6-sulphonic acid) (ABTS(center dot+)) and nitric oxide (NO) radicals. The screened compounds showed potent scavenging activities against DPPH center dot, ABTS(center dot+) and NO radicals. In order to further extend on studies and to obtain a deep insight into structure activity relationship of this class of compounds, we designed N-substitution of indole moiety with the aim to study its antioxidant potential.
CsF promoted rapid synthesis of spirooxindole‐pyran annulated heterocycles at room temperature in ethanol
作者:Yogesh B. Wagh、Swapnil A. Padvi、Pramod P. Mahulikar、Dipak S. Dalal
DOI:10.1002/jhet.3846
日期:2020.3
straightforward synthetic strategy for the construction of functionalized spirooxindole‐pyranannulatedheterocycles is described. The procedure is based on CsF‐promotedrapid tandem Knoevenagel‐Michael‐Cyclocondensation reaction of isatin, malononitrile, and 4‐hydroxycoumarin/barbituric acids/pyrazolone at roomtemperature in ethanol. This methodology has various advantages like easy operational, excellent