TWO APPROACHES TO REGIO- AND STEREOSELECTIVE SYNTHESIS OF <i>N</i>-UNSUBSTITUTED 3-ARYL-4-(TRIFLUOROMETHYL)-4<i>H</i>-SPIRO[CHROMENO[3,4-<i>c</i>]PYRROLIDINE-1,3'-OXINDOLES]
DOI:
https://doi.org/10.1007/6249Keywords:
azomethine ylides, benzylamines, isatins, 3-nitro-2-(trifluoromethyl)-2H-chromenes, L-phenylglycine, spirochromeno[3, 4-c]pyrrolidines, spiro[pyrrolidine-1, 3'-oxindoles], cytotoxic activity, 1, 3-dipolar cycloaddition.Abstract
A regio- and stereoselective method for the synthesis of N-unsubstituted 3-aryl-4-(trifluoromethyl)-4H-spiro[chromeno[3,4-c]pyrrolidine1,3'-oxindoles] in 24–79% yields, based on the three-component reaction of 3-nitro-2(trifluoromethyl)-2H-chromenes with azomethine ylides generated in situ from benzylamines and isatins by refluxing in CH2Cl2 for 24 h has been developed. 3-Phenyl-4(trifluoromethyl)-4H-spiro[chromeno[3,4-c]pyrrolidine-1,3'-oxindoles] were obtained in 36–71% yields via the three-component reaction of 3-nitro-2-(trifluoromethyl)-2H-chromene, isatins, and L-phenylglycine proceeding in EtOH at 60°C for 5 h. The resulting compounds exhibited cytotoxic activity against human cervical cancer HeLa cells in the micromolar concentration range.
