反应详情

To the above-prepared [4-(2-ethyl-5-phenyl-2H-pyrazol-3-yl)-4-oxo-but-2-ynyl]-carbamic acid tert-butyl ester in EtOH (5 mL), hydrazine monohydrate was added (excess, 5 drops), and the mixture was stirred at room temperature for 2 hours. The resulting mixture was concentrated in vacuo to a thick oil, diluted with ethyl acetate, washed sequentially with water and brine, dried over Na2SO4, filtered, and concentrated in vacuo. Flash chromatography (silica gel, hexanes/ethyl acetate gradient) provided the title compound (175 mg, 98% yeild) as a white foam. 1H NMR (CDCl3, 400 MHz): 7.86 (d, 2H); 7.39 (dd, 2H); 7.28 (dd, 1H); 6.72 (s, 1H); 6.36 (s, 1H); 5.12 (broad dd, 1H); 4.58 (q, 2H); 4.31 (d, 2H); 1.49 (s, 9H).

1. concentrationThe resulting mixture was concentrated in vacuo to a thick oil
2. additiondiluted with ethyl acetate
3. washwashed sequentially with water and brine
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo