Trifluoroacetic acid → 5-Chloro-3-nitro-4-(4-(thiazol-4-ylmethyl)piperazin-1-yl)pyridin-2-amine

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Reaction Steps

tert-Butyl 4-(thiazol-4-ylmethyl)piperazine-1-carboxylate (0.220 g, 0.79 mmol, 1.1 eq) was dissolved in DCM (2 mL) and the mixture cooled in a ice-water bath before the dropwise addition of TFA (2 mL). Stirring was continued at this temperature for 1 h. The solvents were removed in vacuo and the resulting crude material was azeotroped with toluene and dried. 4-(piperazin-1-ylmethyl)thiazole (supposedly 0.140 g, 0.79 mmol, 1.1 eq) was suspended in iPrOH (0.8 mL) and DIPEA (0.3 mL). To this solution, 4,5-dichloro-3-nitropyridin-2-amine (0.15 g, 0.72 mmol, 1 eq) was added and the mixture was heated and stirred for 17 h at 65° C. The mixture was filtered, washed with iPrOH (3×3 mL), Et2O (2×3 mL) and dried to give the title compound as a bright yellow powder (0.080 g, 27%); 1H-NMR (500 MHz, DMSO-d6): δ 2.52-2.60 (m, 4H, piperazine N(CH2)2), 3.07 (m, 4H, piperazine N(CH2)2), 3.72 (s, 2H, NCH2), 6.94 (s, 2H, NH2), 7.54 (s, 1H, thiazole 5-H), 8.05 (s, 1H, pyridine 6-H), 9.04 (s, 1H, thiazole 2-H); LC (Method B)-MS (ESI, m/z): Rt=1.71 min—355/357 [(M+H)+, Cl isotopic pattern].

Provenance & Evidence