Tetrahydrofuran → Rac-8-ethyl-2,3-diphenyl-5,6,7,8-tetrahydropyrido[2,3-b]pyrazine

Participants

Reaction Steps

To a mixture comprising tert-butyl 8-bromo-2,3-diphenyl-7,8-dihydropyrido[2,3-b]pyrazine-5(6H)-carboxylate (Intermediate H) (200 mg, 0.429 mmol) and silver nitrate (0.728 mg, 4.29 μmol) in diethyl ether (4 ml) under nitrogen at RT was added 1-Methylmagnesium bromide in THF (0.557 ml, 0.557 mmol). The reaction mixture was left to stir at RT for 3 h under an atmosphere of nitrogen. The mixture was poured into a saturated ammonium chloride solution (10 ml) and extracted with EtOAc (2×10 ml). The organic extracts were combined, dried over MgSO4, filtered and concentrated in vacuo. The resulting crude product was purified by chromatography on silica eluting with 0-30% EtOAc/iso-hexane to afford the title compound;

Provenance & Evidence