反应详情

温度

25 °C

To a solution of 1-(3-methyl-butylamino)-1H-pyrrole-2-carboxylic acid allyl ester (Example 1c, 2.8 g, 16 mmol) in dichloromethane (70 mL) was added O-benzylhydroxylamine hydrochloride (2.56 g, 16 mmol). Tetrakis(triphenylphosphine)palladium(0) (3.6 g, 3.2 mmol) was added and the reaction mixture was heated at reflux for 16 h. The crude mixture was allowed to cool to 25° C. The solvent was removed in vacuo and redissolved in ethyl acetate (150 mL) and then washed with 10% aqueous hydrochloric acid solution (3×50 mL) and water (50 mL). The organic layer was dried over magnesium sulfate, filtered and concentrated in vacuo. The crude product was purified by column chromatography (Merck silica gel 60, 40-63 μm, ethyl acetate/hexane, 20-60%) to afford the desired product, 1-(3-methyl-butylamino)-1H-pyrrole-2-carboxylic acid (2.5 g, 13 mmol, 82% yield) as a yellow oil. 1H NMR (400 MHz, CDCl3) δ 0.94 (6H, d, J=6.4 Hz), 1.41-1.47 (2H, q, J=15.2 Hz, J2=6.8 Hz), 1.68 (1H, m), 6.18 (1H, dd, J1=4.0 Hz, J2=2.8 Hz), 6.98-7.02 (2H, m).

1. temperaturethe reaction mixture was heated
2. temperatureat reflux for 16 h
3. customThe solvent was removed in vacuo
4. dissolutionredissolved in ethyl acetate (150 mL)
5. washwashed with 10% aqueous hydrochloric acid solution (3×50 mL) and water (50 mL)
6. dry with materialThe organic layer was dried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe crude product was purified by column chromatography (Merck silica gel 60, 40-63 μm, ethyl acetate/hexane, 20-60%)