N-bromobutanimide → 3-bromo-5-(tetrahydro-2H-pyran-4-yl)pyrazin-2-amine

Participants

Reaction Conditions

Reaction Steps

To an ice cold solution of 5-(tetrahydro-2H-pyran-4-yl)pyrazin-2-amine (2.8 g, 15.6 mmol) in CH3CN (52 mL) was added NBS (2.78 g, 15.62 mmol) in two portions at 0° C. The reaction mixture was stirred at 0° C. for 1 h. The reaction mixture was diluted with ethyl acetate and was washed with saturated sodium carbonate solution, water, brine, dried and concentrated. The crude 3-bromo-5-(tetrahydro-2H-pyran-4-yl)pyrazin-2-amine (3.9 g, 97%) was used for the next step without further purification. LCMS (m/z): 258/260 (MH+), 0.52 min; 1H NMR (400 MHz, CDCl3) δ ppm 7.83 (s, 1H), 4.90 (br. s., 2H), 4.14-4.02 (m, 2H), 3.59-3.43 (m, 2H), 2.83 (d, J=5.5 Hz, 1H), 1.91-1.77 (m, 4H).

Provenance & Evidence