反应详情

To a solution of 5-formyl-3-methyl-1H-pyrrole-2-carboxylic acid (306.3 mg, 2 mmol) in DMF 5 mL was added HOBt (324.3 mg, 2.4 mmol), EDC (460.1 mg, 2.4 mmol) and then 1-methylpiperazine (0.27 mL, 2.4 mmol). The mixture was stirred at room temperature under nitrogen for overnight. The reaction was diluted with ethyl acetate and washed with sodium bicarbonate. The aqueous layer was extracted several times with ethyl acetate. The combined organic layer was washed with brine, dried, concentrated and column chromatographed (MeOH/DCM) to give 310 mg (66%) of 4-methyl-5-(4-methyl-piperazine-1-carbonyl)-1H-pyrrole-2-carbaldehyde as a light yellow foam solid. 1H NMR (360 MHz, DMSO-d6) 12.20 (br s, 1H, NH), 9.47 (s, 1H, CHO), 6.80 (s, 1H), 3.58 (m, 4H, 2×CH2), 3.44 (m, 4H, 2×CH2), 2.03 (s, 3H, CH3).

1. washwashed with sodium bicarbonate
2. extractionThe aqueous layer was extracted several times with ethyl acetate
3. washThe combined organic layer was washed with brine
4. customdried
5. concentrationconcentrated
6. customcolumn chromatographed (MeOH/DCM)