Tributylphosphine → 3-(1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazol-4-yl)-1-((6-methoxypyridin-2-yl)methyl)imidazolidine-2,4-dione

Participants

Reaction Steps

3-(1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazol-4-yl)imidazolidine-2,4-dione (100 mg, 0.4 mmol), (6-methoxy-pyridin-2-yl)-methanol (example 10-75a) (101 mg, 0.7 mmol), tributylphosphine (147 mg, 0.7 mmol), and 1,1″″-azobis(N,N-dimethylformamide) (125 mg, 0.7 mmol) were dissolved in THF (5 mL) and stirred at room temperature for 15 hours. The reaction was diluted with brine (100 mL) and extracted with ethyl acetate (2×, 100 mL). The combined organic extracts were dried over magnesium sulfate, filtered and concentrated on the rotovap. The residue was taken up in methanol (5 mL) and purified by reversed phase HPLC (5 to 95% acetonitrile in H2O: 25 minute gradient). The pure fractions were combined, concentrated then re-dissolved in ethyl acetate/hexane (1:9). The solution was cooled at 5° C. for 15 hrs, where a white solid formed. The precipitate was collected to afford 3-(1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazol-4-yl)-1-((6-methoxypyridin-2-yl)methyl)imidazolidine-2,4-dione (5 mg, 4%) as a white solid. 1H NMR (DMSO-d6, 400 MHz): δ2.11 (s, 3H), 2.37 (s, 3H), 3.74 (s, 3H), 4.17 (s, 2H), 4.54 (s, 2H), 5.17 (s, 2H), 6.69 (d, J=7.6 Hz, 1H), 6.96 (d, J=6.8 Hz, 1H), 7.67 (d, J=6.8 Hz, 1H), 7.76 (s, 1H), 8.17 (s, 1H). MS M+H calculated 397.2; found 397.2. The title compound was shown to inhibit hT2R08 bitter receptor and had an IC50 of 0.23 μM.

Provenance & Evidence