4-[2-[(3-Ethyl-4-methyl-2-oxo-3-pyrrolin-1-yl)carboxamido]ethyl]benzenesulfonamide

119043-16-2

119018-29-0

38.0 kg of methanol and 5.1 kg of industrial ammonia were sequentially added to a 100 L reactor and stirring was initiated. The crude wet product of Intermediate 2 was added slowly at 20-30°C and the reaction was maintained for 2 hours. The progress of the reaction was monitored by HPLC and after the reaction was complete, filtration was carried out and the filter cake was washed with deionized water. The obtained crude wet product of white Intermediate 3 was directly transferred to a 200 L reactor. Subsequently, 110.0 kg of methanol was added, the reaction temperature was raised and stirring was continued for 4 hours. After completion of the reaction, the mixture was cooled to 20-25 °C, the product was separated by filtration and dried to obtain 8.47 kg of white solid Intermediate 3 refined product, with purity >99% and interstitial isomer impurity content of 0.2% by HPLC.