5-Bromopyrimidine → tert-Butyl 4-(pyrimidin-5-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

5-Bromo pyrimidine (1.0 g, 6.29 mmol) and 1-Boc-piperazine (1.17 g, 6.28 mmol) were dissolved in toluene (20 mL) and the solution was purged with argon for 10 min. Sodium tert-butoxide (816 mg, 8.49 mmol) and catalytic Pd(PtBu3)2 (320 mg, 0.63 mmol) were added and the reaction mixture was heated to 120° C. for 10 h. The reaction mixture was cooled to room temperature, diluted with EtOAc and filtered through Celite. The organic layer was washed with water and brine, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The crude product was purified by column chromatography (silica 60-120 mesh, eluent 80% EtOAc in petroleum ether) to get tert-butyl 4-(pyrimidin-5-yl)piperazine-1-carboxylate (700 mg, yield 42%). 1H NMR (300 MHz, MeOD) δ 8.57 (s, 1H), 8.48 (m, 2H), 3.61-3.58 (m, 4H), 3.30-3.27 (m, 4H), 1.47 (s, 9H). MS (ESI) m/z: Calculated for C13H20N4O2: 264.16. found: 265.0 (M+H)+

Provenance & Evidence