反应详情

To a stirred solution of p-tolylhydrazine hydrochloride (100 g, 630 mmol) in EtOH (1251 mL) was added 4,4-dimethyl-3-oxopentanenitrile (88 g, 699 mmol) and HCl (62.5 mL, 750 mmol). The resulting mixture was stirred at reflux overnight. The reaction mixture was cooled to room temperature and concentrated in vacuo to c.a. ⅓ of the original volume. The reaction mixture was then cooled in an ice-bath and taken to c.a. pH 8-9 with 6M aq NaOH. The reaction mixture was extracted with diethyl ether (500 mL) and the organic phase washed with water (2×300 mL) before being dried over magnesium sulphate and concentrated in vacuo to afford an orange solid. The solid was suspended in iso-hexane and stirred at reflux for 2.5 h before being cooled and filtered whilst still hot to yield the subtitle product 3-tert-butyl-1-p-tolyl-1H-pyrazol-5-amine as a pale brown solid (76.5 g, 52%); Rt 1.31 min (Method 1); m/z 230 (M+H)+ (ES+); 1H NMR δ: 1.20 (9H, s), 2.32 (3H, s), 5.10 (2H, br s), 5.35 (1H, s), 7.24 (2H, d), 7.42 (2H, m).

1. temperatureat reflux overnight
2. concentrationconcentrated in vacuo to c.a
3. temperatureThe reaction mixture was then cooled in an ice-bath
4. extractionThe reaction mixture was extracted with diethyl ether (500 mL)
5. washthe organic phase washed with water (2×300 mL)
6. dry with materialbefore being dried over magnesium sulphate
7. concentrationconcentrated in vacuo
8. customto afford an orange solid
9. stirringstirred
10. temperatureat reflux for 2.5 h
11. temperaturebefore being cooled
12. filtrationfiltered whilst still hot