反应详情

温度

90 °C

204 a) An oven dried tube was charged with 1-iodo-3-nitro-benzene (2.60 g, 10.4 mmol), 4-methyl-piperazin-2-one (1.00 g, 8.76 mmol), copper(I) iodide (85.0 mg, 0.446 mmol), (1R,2R)-N,N′-dimethyl-cyclohexane-1,2-diamine (0.14 mL, 0.89 mmol), potassium phosphate (3.75 g, 17.7 mmol) and 1,4-dioxane (10 mL). The tube was carefully evacuated and backflushed with nitrogen three times then sealed. The mixture was heated at 90° C. for 24 hours then cooled to room temperature and diluted with dichloromethane (20 mL). The mixture was filtered through a plug of diatomaceous earth and the filtrate was evaporated. The residue was purified via chromatography using an ISCO automated purification apparatus (silica gel column 40 g and 0%→4% methanol:dichloromethane). 4-Methyl-1-(3-nitro-phenyl)-piperazin-2-one was isolated as a red-brown waxy solid (1.13 g, 55%). 1H NMR (400 MHz, CDCl3, δ, ppm): 8.20 (s, 1H), 8.13 (d, J=7.5 Hz, 1H), 7.73 (d, J=8.0 Hz, 1H), 7.57 (t, J=8.2 Hz, 1H), 3.79 (t, J=5.1 Hz, 2H), 3.31 (s, 2H), 2.83 (t, J=5.2 Hz, 2H), 2.42 (s, 3H). MS=236 (MH)+.

1. custom204 a) An oven dried tube
2. customThe tube was carefully evacuated
3. customthen sealed
4. temperaturethen cooled to room temperature
5. additiondiluted with dichloromethane (20 mL)
6. filtrationThe mixture was filtered through a plug of diatomaceous earth
7. customthe filtrate was evaporated
8. customThe residue was purified via chromatography
9. custompurification apparatus (silica gel column 40 g and 0%→4% methanol:dichloromethane)