13754-86-4

16806-93-2

13754-86-4

The general procedure for the synthesis of 1,5,6,7-tetrahydro-4H-indol-4-one from 6,7-dihydro-4(5H)-benzofuranone is as follows: 6,7-dihydro-4(5H)-benzofuranone (0.10 g, 0.73 mmol) was dissolved in 20% aqueous ethanol (ca. 2 mL) along with the corresponding amine (3 equiv.) in an airtight tube at 150°C, respectively, and was Heating for 12 h or 36 h, respectively. Upon completion of the reaction, the reaction mixture was poured into water (10 mL) and the resulting aqueous solution was extracted with dichloromethane (3 x 10 mL). The organic extracts were combined, dried with anhydrous magnesium sulfate and concentrated to give a brown residue. This residue was purified by silica gel column chromatography with a solvent mixture of ethyl acetate/petroleum ether as eluent.