Diisopropylethylamine → 5-Chloro-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 (0.126 g, 0.45 mmol) in dichloromethane (3.7 ml) and TFA (5 ml) was stirred at room temperature for 1.5 h then concentrated in vacuo, and the resulting residue was dried in vacuo. Part of this material (estimated 0.15 mmol) was dissolved in isopropanol (3 ml) and to this solution 2-amino-4,5-dichloro-3-nitropyridine (0.031 g, 0.15 mmol) was added followed by diisopropylethylamine (0.15 ml, 0.80 mmol). The reaction mixture was stirred at 45° C. for 20 h, then allowed to cool to room temperature and diluted with isopropanol (3 ml). The resulting yellow precipitate was collected by filtration, washed with isopropanol (2×3 ml), diethyl ether (2×3 ml), and dried (0.038 g, 73%); 1H-NMR (500 MHz, DMSO-d6) 2.38 (s, 3H, isoxazole 5-CH3), 2.52 (br s 4H, piperazine N(CH2)2), 3.06 (br t, J=4.1 Hz, 4H, piperazine N(CH2)2), 3.56 (s, 2H, NCH2 isoxale), 6.21 (s, 1H, isoxazole 4-H), 6.96 (s, 2H, NH2), 8.06 (s, 1H, pyridine 6-H);

Provenance & Evidence