365996-05-0

420-04-2

79099-07-3

365996-05-0

To a 100 mL single-necked flask were added N-Boc-4-piperidone (10 g, 50 mmol), sulfur powder (3.22 g, 100 mmol), cyanamide (4.36 g, 100 mmol), and pyridine (40 mL). The reaction mixture was heated to 130 °C and kept for 90 min. After completion of the reaction, it was cooled to room temperature and the solid product was collected by filtration. The solid was washed with ethyl acetate and dried to give the dark brown solid product tert-butyl 2-amino-6,7-dihydrothiazolo[5,4-c]pyridine-5(4H)-carboxylate (9.7 g, 76% yield).