Triethylamine → 3-methyl-5-(4-methylpiperazine-1-carbonyl)-1H-pyrrole-2-carbaldehyde

Participants

Reaction Steps

To a suspension of 5-formyl-4-methyl-1H-pyrrole-2-carboxylic acid (1.53 g, 10 mmol) in DMF (20 mL) was added 1-methylpiperazine (1.2 g, 12 mmol), followed by 1-ethyl-3-(3-dimethylaminopropyl)carboiimide hydrochloride (EDAC, 2.3 g, 12 mmol), 1-hydroxybenzotriazole (HOBt, 1.6g, 12 mmol) and triethylamine (3.2 mL, 24 mmol). The reaction mixture was stirred at room temperature for 2 days. The reaction was concentrated, diluted with water and extracted with ethyl acetate (5×). The combined ethyl acetate was concentrated to a volume of 20 mL and triturated with hexane (10 mL). The resulting solid was collected by vacuum filtration to give 1.6 g (68%) of 3-methyl-5-(4-methyl-piperazine-1-carbonyl)-1H-pyrrole-2-carbaldehyde as a yellow solid. 1H NMR (300 MHz, DMSO-d6) δ 12.21 (s, 1H, NH), 9.7 (s, 1H, CHO), 6.35 (s, 1H), 3.58 (m, 4H 2×CH2), 2.30 (m, 7H, 2×CH2 & CH3), 2.18 (s, 3H, CH3). MS 236 [M++1].

Provenance & Evidence