反应详情

1-{2-[4-(2-Nitro-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazin-6-yloxymethyl)-phenoxy]-acetyl}-piperidin-4-one. A solution of [4-(2-nitro-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazin-6-yloxylmethyl)-phenoxy]-acetic acid tert-butyl ester (130 mg, 0.32 mmol) in TFA (1.0 mL) and dichloromethane (2.0 mL) was stirred at room temperature for 1.5 h. Solvent was evaporated to give [4-(2-nitro-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazin-6-yloxymethyl)-phenoxy]-acetic acid. To a solution of the above acid in dichloromethane (6.0 mL) under N2 was added diisopropylethylamine (0.20 mL), 4-piperidone hydrochloride monohydrate (98 mg, 0.64 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (80 mg, 0.42 mmol), 1-hydrobenzotriazole (52 mg, 0.38 mmol). The mixture was stirred at room temperature for 24 h. The reaction mixture was diluted with dichloromethane, washed with saturated NaHCO3 and 1 N HCl solution, dried over sodium sulfate, and concentrated in vacuo. The crude product was purified by preparative TLC plates (5% MeOH in dichloromethane) to give the title product as oil (28.0 mg, 20%). ESI MS m/z 431 (M+H+); 1H NMR (400 MHz, CDCl3) δ 7.37 (s, 1H), 7.26 (d, J=8.4 Hz, 2H), 6.94 (d, J=8.4 Hz, 2H), 4.77 (s, 2H), 4.67-4.53 (m, 3H), 4.32 (d, J=12.0 Hz, 1H), 4.15-4.07 (m, 3H), 3.91-3.85 (m, 4H), 2.50-2.45 (m, 4H).

1. customSolvent was evaporated