Hydrochloric Acid → 1-Methyl-4-(3-nitrophenyl)piperazine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of diisopropyl azodicarboxylate (51.4 mmol, 1.3 eq) in EtOAc (20 mL) was added to N2-(2-hydroxyethyl)-N2-methyl-N1-(3-nitrophenyl)glycinamide (10 g, 39.5 mmol) and tributylphosphine (13 mL, 51.4 mmol, 1.3 eq.) in EtOAc (50 mL) over a 60-min period during which time the internal reaction temperature was maintained between 25° C. and 30° C. Ethanolic HCl (2.0 M solution, 20 mL) was added dropwise and the resulting slurry was cooled to 0° C. and stirred for an additional hour. The solid was collected by filtration, washed with isopropanol and dried in vacuo at 40° C. for 18 h to give the desired 1-methyl-4-(3-nitrophenyl)piperazine, which was used in the next step without further purification (8.43 g, 79% yield) 1H NMR (400 MHz, DMSO-d6) δ ppm 11.90 (1H, br s) 8.28 (1H, t, J=2.15 Hz) 8.20 (1H, ddd, J=8.08, 2.27, 1.01 Hz) 7.85 (1H, d, J=2.02 Hz) 7.84 (1H, d, J=2.02 Hz) 7.77 (1H, t, J=8.08 Hz) 4.04 (3H, br. s.) 3.66 (1H, br. s.) 3.56 (1H, br. s.) 2.92 (4H, s).

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