Cesium carbonate → 3-(1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazol-4-yl)-1-(2-phenoxyethyl)imidazolidine-2,4-dione

Participants

Reaction Steps

3-(1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazol-4-yl)imidazolidine-2,4-dione (example 10-1) (200 mg, 0.7 mmol), (2-bromoethoxy)benzene (200 mg, 1 mmol), and cesium carbonate (325 mg, 1 mmol) were irradiated in the microwave reactor at 85° C. for 20 minutes. The reaction was cooled to room temperature, diluted with aqueous 1N HCl (100 mL) and extracted with ethyl acetate (3×, 75 mL). The combined organic extracts were dried over sodium sulfate, filtered and concentrated. The residue was taken up in methanol (10 mL) and purified by reversed phase HPLC (5 to 95% acetonitrile in H2O: 25 minute gradient). The pure fractions were pooled, concentrated then re-dissolved in absolute ethanol and concentrated on the rotovap (4×) to afford 3-(1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazol-4-yl)-1-(2-phenoxyethyl)imidazolidine-2,4-dione (150 mg, 54%) as a white solid. 1H NMR (CDCl32.18, 400 MHz): δ (s, 3H), 2.41 (s, 3H), 3.86 (t, J=5.2 Hz, 2H), 4.19 (t, J=4.4 Hz, 2H), 4.25 (s, 2H), 5.05 (s, 2H), 6.88 (dd, J=9.2, 1.2 Hz, 2H), 7.00 (dt, J=7.6, 1.2 Hz, 1H), 7.27-7.32 (m, 2H), 7.89 (s, 1H), 8.05 (s, 1H). MS M+H calculated 396.17; found 396.1. Melting point: 117-118° C. The title compound was shown to inhibit hT2R08 bitter receptor and had an IC50 of 0.06 μM.

Provenance & Evidence