Synthesis
GENERAL METHOD: 2-Indolone (200 mg, 1 eq.) was dissolved in methanol (5 mL) and piperidine (1.5 eq.) and 3,5-dimethyl-2-pyrrolecarboxaldehyde (1.2 eq.) were added sequentially. The reaction mixture was heated to reflux with continuous stirring for 1 to 4 hours. After completion of the reaction, it was cooled to room temperature. The reaction mixture was filtered and the resulting solid was washed three times with methanol. The solid product was collected and dried under vacuum to remove residual methanol to give the final target product (Z)-3-((3,5-dimethyl-1H-pyrrol-2-yl)methylene)dihydroindol-2-one.
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