Diisopropylethylamine → 5-Bromo-3-nitro-4-(4-(pyridin-4-ylmethyl)piperazin-1-yl)pyridin-2-amine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a mixture of 5-bromo-4-chloro-3-nitro-pyridin-2-ylamine (0.126 g, 0.50 mmol) and isopropanol (9 ml) was added 1-[(4-pyridyl)-methyl]-piperazine (0.097 g, 0.55 mmol) followed by diisopropylethylamine (0.10 ml, 0.57 mmol). The reaction mixture was heated at 45° C. for 20 h, then allowed to cool to room temperature. The precipitate was collected by filtration and washed with isopropanol and diethyl ether. The title compound was thus obtained as an orange solid (0.080 g). The filtrate was concentrated in vacuo, and purification of the residue on a isolute silica column using 1 to 5% methanol in ethyl acetate as eluant gave an additional 0.055 g of the product (total yield: 68%); 1H-NMR (500 MHz, DMSO-d6) 2.53 (br s, 4H, piperazine N(CH2)2), 3.08 (br s, 4H, piperazine N(CH2)2), 3.57 (s, 2H, NCH2), 6.97 (s, 2H, NH2), 7.34 (d, J=5.88 Hz, 2H), and 8.51 (d, J=4.48 Hz, 2H) (pyrid-4-yl protons), 8.16 (s, 1H, 6-H); LC (Method B)-MS (ESI, m/z): Rt=2.00 min—393, 395 [(M+H)+, Br isotopic pattern].

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