反应详情

温度

50 °C

1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazole-4-carbonyl azide (Example 10-1a) (10 g, 41.0 mmol) is stirred under nitrogen in dry toluene (150 mL) along with molecular sieves at reflux until no emission of nitrogen was observed, which indicates complete conversion of 1-((3, 5-dimethylisoxazol-4-yl)methyl)-1H-pyrazole-4-carbonyl azide into 4-((4-isocyanato-1H-pyrazol-1-yl)methyl)-3,5-dimethylisoxazole. The solution was cooled down to 50° C. and ethyl 2-amino-2-methylpropanoate hydrochloride (5.30 g, 41.0 mmol) was added in one portion. Stirring continued for 3 hours at 50° C. followed by reflux for 12 hours. The mixture was filtered over a pad of celite. The filtrate was concentrated on the rotovap and the residue was purified over silica gel using 25% ethyl acetate in hexanes. Yield 65% (8.00 g), white solid. 1H NMR (DMSO-d6, 400 MHz): . s, 6H), 2.15 (s, 3H), 2.41 (s, 3H), 5.18 (s, 2H), 7.78 (d, J=0.4 Hz, 1H), 8.16 (d, J=0.4 Hz, 1H), 8.59 (br s, 1H). MS 304 (MH+). This compound was shown to inhibit hT2R08 bitter receptor and had an IC50 of 2.27 μM.

1. temperatureat reflux until no emission of nitrogen
2. temperatureby reflux for 12 hours
3. filtrationThe mixture was filtered over a pad of celite
4. concentrationThe filtrate was concentrated on the rotovap
5. customthe residue was purified over silica gel using 25% ethyl acetate in hexanes