反应详情

To a stirring suspension of 5-amino-1-benzyl-4-(4-methylphenyl)-1H-pyrazol-3-ol (Preparation 42) (2.4 g) and cesium carbonate (8.4 g) in dimethylformamide (30 ml) under nitrogen at room temperature was added 2-bromoethyl acetate (1.44 g) and the reaction mixture stirred overnight. The reaction was quenched with 2M hydrochloric acid (100 ml) and extracted into ethyl acetate (2×100 ml). The two combined organic extracts were further washed with water (2×100 ml), then dried (MgSO4) and the solvent removed under reduced pressure to give the crude material. This was purified using the Biotage™ Flash 40 system (90 g Silica) with a gradient elution of hexane 75% to 30%) and ethyl acetate (25% to 70%) to yield the title product as a brown oil.(1.75 g, ca. 60%)

1. customThe reaction was quenched with 2M hydrochloric acid (100 ml)
2. extractionextracted into ethyl acetate (2×100 ml)
3. washThe two combined organic extracts were further washed with water (2×100 ml)
4. dry with materialdried (MgSO4)
5. customthe solvent removed under reduced pressure
6. customto give the crude material
7. customThis was purified
8. washwith a gradient elution of hexane 75% to 30%) and ethyl acetate (25% to 70%)