反应详情

To a suspension of imidazole-2-carboxaldehyde (2.3 g, 23.4 mmol) in 50 mL dioxane is added to ethyl isocyanoacetate (2.9 g, 25.8 mmol) and DBU (3.9 g, 25.8 mmol). After stirring at RT for 5 days, the reaction is neutralized with 10% AcOH. The solvent is removed in vacuo. The residue is taken up in EtOAc/H2O, the aqueous layer is extracted with CHCl3, dried (MgSO4), filtered and concentrated. The residue is purified by chromatography (Biotage 40M, eluting with 5% MeOH/EtOAc). Ethyl imidazo[1,2-c]pyrimidine-7-carboxylate is obtained (1.4 g, 32%) as an off-white solid. 1H NMR (400 MHz, CDCl3) δ9.14, 8.43, 7.88, 7.81, 4.54-4.48, 1.49-1.44.

1. customThe solvent is removed in vacuo
2. extractionthe aqueous layer is extracted with CHCl3
3. dry with materialdried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue is purified by chromatography (Biotage 40M, eluting with 5% MeOH/EtOAc)