反应详情

10% Palladium on carbon (0.2 eq) was added to a N2-flushed mixture of ethyl 2,6-dichloro-5-nitropyrimidine-4-carboxylate (1 eq) and magnesium oxide (2 eq) in 1,4-dioxane (0.15 M). The reaction was purged with H2 under atmospheric pressure at rt. After 16 h additional portions of 10% Pd/C (0.3 eq) and MgO (5 eq) were added and the reaction continued to purge with H2 under atmospheric pressure for 6 h at rt. The crude solids were filtered through a pad of Celite on a paper lined Buchner funnel and washed with CH2Cl2. The filtrate was transferred to a separatory funnel, washed twice with H2O and once with brine, then dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The crude product was dissolved in CH2Cl2, loaded onto a SiO2 column, and purified by flash chromatography (10-20-30% EtOAc in hexanes) to give ethyl 5-amino-2-chloropyrimidine-4-carboxylate. LC/MS (m/z): 202.0 (MH+).

1. customflushed
2. customThe reaction was purged with H2 under atmospheric pressure at rt
3. customto purge with H2 under atmospheric pressure for 6 h at rt
4. filtrationThe crude solids were filtered through a pad of Celite on a paper
5. washwashed with CH2Cl2
6. customThe filtrate was transferred to a separatory funnel
7. washwashed twice with H2O and once with brine
8. dry with materialdried over anhydrous Na2SO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. dissolutionThe crude product was dissolved in CH2Cl2
12. custompurified by flash chromatography (10-20-30% EtOAc in hexanes)