Diisopropylethylamine → 3-(5-amino-4-benzoyl-3-methoxy-pyrazol-1-yl)-N-cyclopropyl-4-methyl-benzamide

Participants

Reaction Steps

Sodium (317 mg, 13.8 mmol) was added to methanol (10 ml) at 0° C. After all of the sodium was consumed, this solution of sodium methoxide was added to a stirred solution of 2-benzoyl-3,3-bis-methylsulfanyl-acrylonitrile 2 (3.12 g, 12.5 mmol) in dioxane (30 ml) at 0° C. The reaction was warmed to room temperature and then heated to 80° C. for 3 h. The dark red solution was cooled to room temperature and was added to a solution of N-cyclopropyl-3-hydrazino-4-methyl-benzamide trifluoroacetic acid salt (4.00 g, 12.5 mmol) and diisopropylethylamine (2.18 ml, 12.5 mmol) in dioxane (15 ml). The mixture was heated to 85° C. for another 6 h. The solvent was removed in vacuo. The residue was diluted in saturated NaHCO3 solution and was extracted three times with EtOAc. Combined organic layers were dried over MgSO4, filtered and concentrated. The crude product was purified by flash chromatography (SiO2, gradient of 75 to 90% EtOAc/hexanes) and recrystallization from EtOAc to give the desired 3-(5-amino-4-benzoyl-3-methoxy-pyrazol-1-yl)-N-cyclopropyl-4-methyl-benzamide 3 as a white solid (950 mg, 19%). HPLC (4 minute 10-90 gradient) tR 2.33 min; MS m/z 391.2 [M+H]+; 1H NMR (DMSO-d6, 300 MHz) δ 8.50 (d, J=3.4, 1 H), 7.91 (d, J=7.9, 1 H), 7.85 (s, 1 H), 7.61 (d, J=6.9, 2 H), 7.41-7.62 (m, 4 H), 7.00 (bs, 2 H), 3.66 (s, 3 H), 2.87 (m. 1 H), 2.20 (s, 3 H), 0.70 (m, 2 H), 0.85 (m, 2H) ppm; 13C NMR (DMSO-d6, 125 MHz) δ 188.1, 166.0, 159.5, 152.8, 140.1, 139.5, 135.5, 132.9, 131.1, 130.6, 128.1, 128.0, 127.4, 126.8, 91.0, 55.2, 23.0, 15.1, 5.6 ppm.

Provenance & Evidence