Diisopropylethylamine → 5-Bromo-4-[4-(5-methyl-isoxazol-3-ylmethyl)-piperazin-1-yl]-3-nitro-pyridin-2-ylamine

Participants

Reaction Conditions

Reaction Steps

A solution of 4-(5-methyl-isoxazol-3-ylmethyl)-piperazine-1-carboxylic acid tert-butyl ester (0.200 g, 0.71 mmol) in dichloromethane (6 ml) and TFA (8 ml) was stirred at room temperature for 2 h then concentrated in vacuo, and the resulting residue was dried in vacuo. This material (supposedly 0.70 mmol) was dissolved in isopropanol (13 ml) and to this solution 2-amino-5-bromo-4-chloro-3-nitropyridine (0.157 g, 0.63 mmol) was added followed by diisopropylethylamine (0.65 ml, 3.70 mmol). The reaction mixture was stirred at 45° C. for 20 h, then allowed to cool to room temperature and diluted with isopropanol (5 ml). The resulting orange solid was collected by filtration, washed with isopropanol (2×5 ml), diethyl ether (3×5 ml), and dried (0.170 g, 60%); 1H-NMR (500 MHz, DMSO-d6) 2.38 (s, 3H, isoxazole 5-CH3), 2.53 (br s, 4H, piperazine N(CH2)2), 3.05 (br s, 4H, piperazine N(CH2)2), 3.55 (s, 2H, NCH2 isoxazole), 6.21 (s, 1H, isoxazole 4-H), 6.97 (s, 2H, NH2), 8.16 (s, 1H, pyridine 6-H);

Provenance & Evidence