tert-Butyl 4-((2-methylthiazol-4-yl)methyl)piperazine-1-carboxylate (0.380 g, 1.28 mmol, 1.1 eq) was dissolved in DCM (4 mL) and the mixture cooled in a ice-water bath before the dropwise addition of TFA (4 mL). Stirring was continued at this temperature for 1 h. Solvents were removed in vacuo and the resulting crude material was azeotroped with toluene and dried. 2-Methyl-4-(piperazin-1-ylmethyl)thiazole (supposedly 0.250 g, 1.28 mmol, 1.1 eq) was suspended in iPrOH (3.9 mL) and DIPEA (1 mL). To this solution, the 4,5-dichloro-3-nitropyridin-2-amine (0.240 g, 1.16 mmol, 1 eq) was added and the mixture 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 (0.210 g, 44%); 1H-NMR (500 MHz, DMSO-d6): δ 2.52-2.59 (m, 4H, piperazine N(CH2)2), 2.63 (s, 3H, thiazole Me), 3.06 (m, 4H, piperazine N(CH2)2), 3.59 (s, 2H, NCH2), 6.94 (s, 2H, NH2), 7.28 (s, 1H, thiazole 5-H), 8.05 (s, 1H, pyridine 6-H); LC (Method B)-MS (ESI, m/z): R=2.06 min—369/371 [(M+H)+, Cl isotopic pattern].
