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

Participants

Reaction Conditions

Reaction Steps

To 5-(tetrahydro-2H-pyran-4-yl)pyridin-2-amine/acetonitrile solution (1.4 g, 7.85 mmol/30 mL) at 0-5° C. was added portionwise NBS (1.4 g, 7.85 mmol) with internal temperature controlled below 5° C. The resulting mixture was stirred at 0° C. for 1 hour 40 min. The reaction mixture was concentrated under reduced pressure, and the residue was triturated with dilute aqueous NaOH/H2O (1 g/30 mL). The solid suspension was collected via filtration. The filtercake was washed with ice cold water (˜10 mL), and the filtrates were combined, and extracted with EtOAc (20 mL). The EtOAc extract was washed with brine (20 mL), dried over Na2SO4, and concentrated. A light yellow solid was combined with the filter cake, and dried under high vacuum as crude 3-bromo-5-(tetrahydro-2H-pyran-4-yl)pyridin-2-amine. LCMS (m/z) 257.1/259.1 (MH+) 0.39 min. 1H NMR (CDCl3) δ ppm 7.90 (d, J=1.6 Hz, 1H), 7.54 (d, J=2.0 Hz, 1H), 4.80 (br. s., 1H), 4.12-4.02 (m, 2H), 3.54-3.44 (m, 2H), 2.71-2.61 (m, 1H), 1.78-1.68 (m, 4H).

Provenance & Evidence