581060-27-7

895126-44-0

581060-27-7

A reaction was carried out with tert-butyl 4-((carbamoylimidothio)methyl)piperidine-1-carboxylate (1.2, 15 g, 1.00 eq., crude) as raw material with sodium hydroxide (2.2 g, 55.00 mmol, 1.00 eq.) in a mixture of methanol/water (1:2 v/v, 150 mL) under argon protection at 60 °C with stirring for 2 hours. After completion of the reaction, the reaction mixture was cooled to room temperature. The pH of the reaction solution was adjusted with 35% aqueous hydrochloric acid to 7. The reaction solution was extracted with ethyl acetate (3 x 50 mL) and the organic phases were combined. The organic phase was washed with saturated saline (2 x 50 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent: ethyl acetate/petroleum ether=1:8 v/v) to give 5.6 g of yellow oily product in 44% yield. The structure of the product was confirmed by 1H-NMR (400 MHz, CDCl3): δ 4.13 (m, 2H), 2.69 (m, 2H), 2.46 (m, 2H), 1.82 (m, 2H), 1.50 (s, 9H), 1.32 (m, 1H), 1.18 (m, 2H) ppm.