反应详情

To a solution of 4,4-dimethyl-3-oxo-pentanenitrile (5.0 g, 40 mmol) and 3-methoxy-phenylhydrazine hydrochloride (7.0 g, 40 mmol) in anhydrous ethanol (200 mL) was added acetic acid (1.2 mL). The reaction mixture was heated at reflux overnight, then cooled to room temperature and concentrated at reduced pressure. The residue was combined with ethyl acetate (200 mL), and washed with saturated aq NaHCO3, water, and brine. The solution was dried over Na2SO4, evaporated at reduced pressure and the solid residue was re-dissolved in ethanol (100 mL). A solution of 2M HCl in ether was added and the mixture was stirred for 30 min. The solvent was removed at reduced pressure, the solid residue was triturated and washed with hexane (50 mL) and then dried in a vacuum oven overnight to give the product 5-tert-butyl-2-(3-methoxy-phenyl)-2H-pyrazol-3-ylamine hydrochloride (5.46 g, 56%) as an off-white solid. 1H-NMR (DMSO-d6) δ 7.50 (t, 1H), 7.10 (m, 3H), 5.60 (s, 1H), 3.80 (s, 3H), 1.30 (s, 9H); MS LC-MS [M+H]+=246.2, RT=1.90 min.

1. temperatureThe reaction mixture was heated
2. temperatureat reflux overnight
3. concentrationconcentrated at reduced pressure
4. washwashed with saturated aq NaHCO3, water, and brine
5. dry with materialThe solution was dried over Na2SO4
6. customevaporated at reduced pressure
7. dissolutionthe solid residue was re-dissolved in ethanol (100 mL)
8. additionA solution of 2M HCl in ether was added
9. customThe solvent was removed at reduced pressure
10. customthe solid residue was triturated
11. washwashed with hexane (50 mL)
12. customdried in a vacuum oven overnight