反应详情

To a suspension of 4-bromo-1-methyl-1H-pyrrole-2-carboxylic acid (Matrix Scientific, Columbia, S.C.; 390 mg, 1.91 mmol) in 5 mL of DCM at RT was added oxalyl chloride (2.0 M solution in DCM, 1.912 mL, 3.82 mmol) followed by 3 drops of DMF. After stirring at RT for 30 min, the mixture was concentrated under reduced pressure. The remaining off white solid was cooled with an ice bath, NH3 (0.5 M solution in 1,4-dioxane, 15.3 mL, 7.65 mmol) was added. After stirring at RT for 30 min, the mixture was diluted with 50 mL of EtOAc and washed with 2×15 mL of water. The organic layer was dried over Na2SO4 and concentrated to give 4-bromo-1-methyl-1H-pyrrole-2-carboxamide (329 mg, 85% yield) as a brown crystalline solid that was used without further purification. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.51 (1H, br.), 7.08 (1H, d, J=1.8 Hz), 7.01 (1H, br.), 6.86 (1H, d, J=1.8 Hz), 3.80 (3H, s). m/z (ESI, +ve) 202.9/204.9 (M+H)+.

1. concentrationthe mixture was concentrated under reduced pressure
2. temperatureThe remaining off white solid was cooled with an ice bath
3. stirringAfter stirring at RT for 30 min
4. washwashed with 2×15 mL of water
5. dry with materialThe organic layer was dried over Na2SO4
6. concentrationconcentrated