4414-89-5

808137-94-2

(3) In a reaction flask, 100 mL of methanol and 100 mL of hydrochloric acid (10 mol/L) were added, and 28.6 g of 3-cyano-7-azaindole (0.2 mol) was dissolved in the mixed solvent, and the reaction was stirred for 10 hours at 80°C. The reaction was carried out at 80°C for 10 hours. Upon completion of the reaction, methanol was removed by rotary evaporation and 100 mL of water was added to the residue and slowly neutralized with saturated sodium bicarbonate solution to pH=8, at which point a large amount of solid precipitated. The suspension was allowed to stand in an ice bath at 0 °C for 3 h to promote complete crystallization. This was followed by diafiltration and the solid product was washed with distilled water to remove inorganic salts. The resulting solid was dried and recrystallized using a mixed solvent of ethyl acetate/petroleum ether to give 30.8 g of methyl 7-azaindole-3-carboxylate in 87.6% yield.