1,1'-Thiocarbonyldi-2(1H)-pyridone → 2-Chloro-5-isothiocyanatopyrazine

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Reaction Steps

A solution of 5-chloropyrazin-2-amine (12.95 g, 100 mmol) and 1,1′-thiocarbonyldipyridin-2(1H)-one (27.9 g, 120 mmol) was stirred in DCM (200 mL) at room temperature for 1 h. The reaction was concentrated to ca. 100 mL volume and filtered through a pad of silica gel (1 L), washing with 10% EtOAc in hexanes. The filtrate was concentrated and dried to afford 2-chloro-5-isothiocyanatopyrazine (14.32 g, 83 mmol, 83% yield). 1H NMR (400 MHz, chloroform-d) δ ppm 8.38 (d, J=1.26 Hz, 1H) 8.18 (d, J=1.26 Hz, 1H). MS (LC/MS) R.T.=1.84; [M+H]+=172.09.

Provenance & Evidence