反应详情

Diaza(1,3)bicyclo[5.4.0]undecane (DBU) (0.04 mL, 0.3 mmol) was added to a solution of ethyl (2E)-4-{[(4-iodo-1H-pyrrol-2-yl)carbonyl]amino}but-2-enoate (X, where R1=OCH2CH3) (0.45 g, 1.3 mmol) in acetonitrile (8 mL) and the reaction mixture was stirred at room temperature for 30 min. The solvent was evaporated under vacuum and the residue purified by flash chromatography (SiO2, hexane-EtOAc 1:1) to obtain compound ethyl (7-iodo-1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazin-4-yl)acetate (XII, where R1=OCH2CH3) as an off-white solid (0.35 g, 79% yield).

1. customThe solvent was evaporated under vacuum
2. customthe residue purified by flash chromatography (SiO2, hexane-EtOAc 1:1)