289483-87-0

289483-82-5

289483-87-0

The general procedure for the synthesis of 7-amino-4-methyl-1H-indole-3-carbonitrile from 4-methyl-7-nitro-1H-indole-3-carbonitrile is as follows: the method of reference Example 3A; synthesis of 7-amino-3-cyano-4-methyl-1H-indole; 12.6 g (62.6 mmol) of 3-cyano-4-methyl-7-nitro-1H- indole was suspended in a solvent mixture of 100 mL of tetrahydrofuran and 100 mL of methanol. The hydrogenation reaction was carried out at room temperature and 3 atm hydrogen pressure with the addition of 430 mg (1.87 mmol) of platinum oxide as catalyst. After completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated to dryness. A mixed solvent of tert-butyl methyl ether and hexane was added to the residue and the precipitated crystals were collected by filtration to give 10.7 g of 7-amino-4-methyl-1H-indole-3-carbonitrile (yield: 99.8%). The product was characterized by 1H-NMR (DMSO-d6): δ (ppm) 2.47 (3H, s), 5.07 (2H, s), 6.34 (1H, d, J = 7.6 Hz), 6.64 (1H, d, J = 7.6 Hz), 8.10 (1H, s), 11.70 (1H, br s).