反应详情

To a stirred solution of 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-1H-pyrazole-3-carboxylic acid (prepared according to the methods described by Barth, et al. in U.S. Pat. No. 5,624,941); 740 mg, 2.01 mmol) and N-benzyl-N-(2,2-diethoxyethyl)amine (450 mg, 2.01 mmol) in methylene chloride (6.5 ml) at room temperature was added 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (464 mg, 2.42 mmol) and then diisopropylethylamine (0.42 ml, 2.2 mmol), dropwise. After stirring for 23 hr, the reaction was concentrated, in vacuo, and then extracted from saturated aqueous sodium bicarbonate with ethyl acetate. The combined organic layers were washed with brine, dried (MgSO4), a concentrated, in vacuo. The crude material (1.05 g) was purified on a Biotage™ Flash 40S column using 0–20% ethyl acetate in hexanes as eluant to afford I-1A-1a as a foam (534 mg, 46%): +ES MS (M+1) 572.1; 1H NMR (500 MHz, CD2Cl2) 1:1 mixture of rotamers, δ 7.51 (br s, 0.5H), 7.47 (d, J=2.1 Hz, 0.5H), 7.38–7.34 (m, 2H), 7.38–7.23 (m, 9H), 7.18–7.11 (m, 2H), 7.03 (s, 0.5H), 6.95 (s, 0.5H), 5.22 (s, 1H), 4.91 (s, 1H), 4.83–4.79 (m, 1H), 3.56–3.07 (m, 6H), 1.20 (t, J=7.0 Hz, 3H), 1.07 (t, J=7.0 Hz, 3H).

1. concentrationthe reaction was concentrated, in vacuo
2. extractionextracted from saturated aqueous sodium bicarbonate with ethyl acetate
3. washThe combined organic layers were washed with brine
4. dry with materialdried (MgSO4)
5. customThe crude material (1.05 g) was purified on a Biotage™ Flash 40S column