1,2-Dimethoxyethane → 5-(3,6-dihydro-2H-pyran-4-yl)pyrazin-2-amine

Participants

Reaction Conditions

Reaction Steps

To a solution of boronic ester (6.64 g, 31.6 mmol), 5-bromopyrazin-2-amine (5 g, 28.7 mmol), and PdCl2(dppf) (2.1 g, 2.87 mmol) was added DME (71.8 mL) and 2 M Na2CO3 solution (24 mL). The reaction mixture was heated at 90° C. for 15 h. The reaction mixture was worked up with EtOAc. The organic layer was washed with water and brine, dried over anhydrous sodium sulfate, filtered off, and concentrated in vacuo. The crude product was purified by flash chromatography (gradient EtOAc in heptanes) yielding 5-(3,6-dihydro-2H-pyran-4-yl)pyrazin-2-amine in 57% yield. LCMS (m/z): 178.1 (MH+), 0.34 min; 1H NMR (400 MHz, CDCl3) δ ppm 8.17-8.03 (m, 1H), 8.04-7.88 (m, 1H), 6.57-6.41 (m, 1H), 4.68-4.42 (m, 2H), 4.42-4.29 (m, 2H), 4.06-3.84 (m, 2H), 2.68-2.47 (m, 2H).

Provenance & Evidence