N-bromobutanimide → 5-Bromo-3-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amine

Participants

Reaction Steps

1-Bromopyrrolidine-2,5-dione (18.57 g, 104.36 mmol) was added portionwise to a solution of 3-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amine (20.8 g, 94.87 mmol) in THF (320 mL) and the solution was stirred at room temperature for 16 hours. The reaction mixture was concentrated and the residue was dissolved in dichloromethane (300 mL), washed with water (2×150 mL), brine, dried over magnesium sulfate and concentrated. The solvent was evaporated and the crude product was purified by flash chromatography on silica gel, eluting with 0 to 10% ethyl acetate in dichloromethane. The solvent was evaporated to dryness to afford 5-bromo-3-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amine (25.5 g, 90%) as a beige solid: 1H NMR Spectrum; (CDCl3) 1.52 (9H, s), 8.23 (1H, s); Mass Spectrum [M+H]+=300.

Provenance & Evidence