反应详情

A mixture of 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-1H-pyrazole-3-carboxylic acid (2,2-diethoxyethyl)-amide (I-1A-1a; 528 mg, 0.92 mmol) and p-toluenesulfonic acid monohydrate (175 mg, 0.92 mmol) in toluene (5 ml) was heated to reflux in round bottom flask fitted with a Dean-Stark condenser. After 1 hour, the reaction was cooled to room temperature, 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 (0.49 g) was purified on a Biotage™ Flash 40S column using 10–20–40% ethyl acetate in hexanes as eluant to afford I-1A-1b as a solid (69 mg, 16%): +ES MS (M+1) 480.1; 1H NMR (500 MHz, CD2Cl2) δ 7.50 (d, J=1.5 Hz, 1H), 7.48 (d, J=8.3 Hz, 1H), 7.42 (dd, J=8.3, 2.1 Hz, 1H), 7.38–7.27 (m, 7H), 7.18 (d, J=8.7 Hz, 2H), 6.95 (d, J=7.5 Hz, 1H), 6.42 (d, J=7.5 Hz, 1H), 5.21 (s, 2H).

1. temperaturewas heated
2. temperatureto reflux in round bottom flask
3. customfitted with a Dean-Stark condenser
4. extractionextracted from saturated aqueous sodium bicarbonate with ethyl acetate
5. washThe combined organic layers were washed with brine
6. dry with materialdried (MgSO4)
7. customThe crude material (0.49 g) was purified on a Biotage™ Flash 40S column