1-Iodo-3-nitrobenzene → 4-Methyl-1-(3-nitrophenyl)piperazin-2-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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)+.

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