反应详情

温度

90 °C

To a solution of 1-isopropyl-3-(thiophen-2-yl)-1H-pyrazole-5-carboxylic acid (0.68 g, 2.9 mmol) in dioxane (10 mL) was added with triethylamine (0.44 g, 4.3 mmol), diphenylphosphorylazide (0.95 g, 3.5 mmol) and trichloroethanol (0.86 g, 5.8 mmol) and the mixture was heated to 90° C. for 4 h. The mixture was poured into 3 M HCl (40 mL) solution and the product was extracted with EtOAc (2×40 mL). The combined organics were washed with brine, dried (Na2SO4) and concentrated in vacuo. Purification by silica gel chromatography provided 2,2,2-trichloroethyl 1-isopropyl-3-(thiophen-2-yl)-1H-pyrazol-5-ylcarbamate (0.88 g, 80% yield) as a white solid. 1H NMR (400 MHz, Acetone-d6): δ 7.36-7.34 (m, 3H), 7.07 (dd, J=5.6 Hz, 4.0 Hz, 1H), 6.52 (s, 1H), 5.83 (t, J=7.2 Hz, 3H), 4.95 (s, 2H), 4.66-4.62 (m, 1H), 1.45 (d, J=6.8 Hz, 6H); MS (ESI) m/z: 382.0 (M+H+).

1. extractionthe product was extracted with EtOAc (2×40 mL)
2. washThe combined organics were washed with brine
3. dry with materialdried (Na2SO4)
4. concentrationconcentrated in vacuo
5. customPurification by silica gel chromatography