反应详情

To a solution of 3-methyl-4-nitropyrazole (Apollo, Cheshire, UK, 500 mg, 3.93 mmol) in DMF (10 ml) was added 55% NaH in oil (198 mg, 4.54 mmol) and the reaction mixture was stirred for 30 min at rt. Then to the reaction mixture was added a solution of 2-bromo-N,N-dimethylacetamide (stage L.3, 720 mg, 4.34 mmol) in DMF (3 ml). The reaction mixture was stirred for 1 h at it then quenched with saturated aqueous NaHCO3 and extracted with EtOAc (2×). The combined organic layers were washed with water (2×), brine, dried over Na2SO4, filtered and evaporated. The crude product was purified by Prep. HPLC (H2O (0.1% TFA)/CH3CN 97:2 to 75:25; reverse phase silica gel). The fractions containing product were collected together, basified with NaHCO3 and concentrated before being extracted with EtOAc (3×). The combined organic layers were washed with brine, dried over Na2SO4, filtered and evaporated to give the title compound as a white solid (HPLC tR 2.06 min (Method A); M+H=213 MS-ES).

1. stirringThe reaction mixture was stirred for 1 h at it
2. customthen quenched with saturated aqueous NaHCO3
3. extractionextracted with EtOAc (2×)
4. washThe combined organic layers were washed with water (2×), brine
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. customevaporated
8. customThe crude product was purified by Prep
9. additionThe fractions containing product
10. customwere collected together
11. concentrationconcentrated
12. extractionbefore being extracted with EtOAc (3×)
13. washThe combined organic layers were washed with brine
14. dry with materialdried over Na2SO4
15. filtrationfiltered
16. customevaporated