1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → (E)-N-((5-fluoro-3-methylbenzo[b]thiophen-2-yl)methyl)-N-methyl-3-(3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazin-7-yl)acrylamide

Participants

Reaction Steps

To a solution of (5-fluoro-3-methylbenzo[b]thiophen-2-yl)-N-methyl methanamine (200 mg, 0.96 mmol) in DMF (5 mL) were added in sequential order (E)-3-(3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazin-7-yl)acrylic acid (185 mg, 0.87 mmol), 1-hydroxybenzotriazole (133 mg, 0.96 mmol), diisopropylethylamine (454 uL, 2.61 mmol), and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide (192 mg, 0.96 mmol). The mixture was stirred at room temperature overnight, cooled in an ice bath and water added with rapid stirring. The product was extracted with ethyl acetate (3×10 mL), dried with sodium sulfate, filtered and concentrated. The crude product was purified using preparative HPLC to give the title compound (45 mg, 13%): 1H NMR (400 MHz, DMSO-d6) δ 11.42 (bs, 1H), 8.19 (s, 1H), 7.89-7.87 (m, 2H), 7.55-7.51 (m, 2H), 7.22-7.18 (m, 2H), 5.12-4.87 (2s, 2H, rotamers), 4.68 (s, 2H), 3.54 (s, 3H), 2.39 (s, 3H). MS (ESI) m/e 412 (C21H18FN3O3S+H)+.

Provenance & Evidence