Potassium Carbonate → 5-Bromo-1-methyl-3-(3-methylisothiazol-5-ylamino)pyrazin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

A sealed tube equipped with a magnetic stirrer was charged with 3-methylisothiazol-5-amine (170 mg, 1.5 mmol), 3,5-dibromo-1-methylpyrazin-2(1H)-one (400 mg, 1.5 mmol), Pd(OAc)2 (84 mg, 0.375 mmol), BINAP (116 mg, 0.188 mmol), K2CO3 (450 mg, 4.5 mmol), and 1,4-dioxane (4 mL). After three cycles of vacuum/nitrogen flush, the mixture was heated at 120° C. in a sealed tube for 18 h. It was then cooled to room temperature and filtered. The filtrate was evaporated under reduced pressure. The residue was purified by silica-gel column chromatography eluting with dichloromethane/methanol (100:1 to 25:1) to afford 331a (220 mg, 50%) as a yellow solid. MS-ESI: [M+H]+ 301.0.

Provenance & Evidence