反应详情

Oxalyl chloride (8.75 mL, 100 mmol) was added to a suspension of 3-nitro-1H-pyrazole-5-carboxylic acid (7.85 g, 50 mmol) in dichloromethane (100 mL) and THF (5.00 mL) at 0° C. and one drop of DMF was then added to the reaction mixture. The reaction mixture was stirred at room temperature for 3 hours. The solvent was evaporated and the residue was redissolved in dichloromethane (100 mL). To the reaction mixture was added a solution of cyclopropanamine (4.16 mL, 60.0 mmol) and pyridine (8.09 mL, 100 mmol) in dichloromethane (10 mL) over a period of 10 minutes. The reaction mixture was stirred overnight and then diluted with ethyl acetate (50 mL), washed with water, dried over MgSO4 and concentrated in vacuo. The crude was purified by silica gel column chromatography (0-5% 2N NH3/CD3ODichloromethane) to give 9.16 g of N-cyclopropyl-3-nitro-1H-pyrazole-5-carboxamide. MS (ESI) m/z 197.1 (M+H). 1H NMR (CD3OD) δ ppm 7.38 (s, 1H), 2.81-2.86 (m, 1H), 0.82 (td, J=7.08, 5.36 Hz, 2H), 0.62-0.68 (m, 2H).

1. customThe solvent was evaporated
2. dissolutionthe residue was redissolved in dichloromethane (100 mL)
3. stirringThe reaction mixture was stirred overnight
4. washwashed with water
5. dry with materialdried over MgSO4
6. concentrationconcentrated in vacuo
7. customThe crude was purified by silica gel column chromatography (0-5% 2N NH3/CD3ODichloromethane)