反应详情

To a solution of 4-iodo-2-methyl-2H-pyrazole-3-carboxylic acid (1.0 g, 3.96 mmol) in tetrahydrofuran (10 mL), under an atmosphere of nitrogen, was added carbonyl diimidazole (0.78 g, 4.36 mmol, 1.1 eq.). The resulting mixture was stirred at room temperature for 1.5 hr before adding sodium borohydride (0.75 g, 19.8 mmol, 3.0 eq.) followed by a solution of methanol in tetrahydrofuran (5 mL), dropwise over a period of 10 min. The resulting mixture was stirred for 3 hr before quenching with 2M aqueous hydrochloric acid (30 mL). This mixture was partition with ethyl acetate (50 mL). The organic phase was washed with 1M aqueous sodium hydrogen carbonate (20 mL), saturated brine (20 mL) and dried over sodium sulphate. The resulting mixture was filtered and the filtrate concentrated under reduced pressure to give the title compound as a brown oil (0.56 g, 60%).

1. stirringThe resulting mixture was stirred for 3 hr
2. custombefore quenching with 2M aqueous hydrochloric acid (30 mL)
3. customThis mixture was partition with ethyl acetate (50 mL)
4. washThe organic phase was washed with 1M aqueous sodium hydrogen carbonate (20 mL), saturated brine (20 mL)
5. dry with materialdried over sodium sulphate
6. filtrationThe resulting mixture was filtered
7. concentrationthe filtrate concentrated under reduced pressure