N,N-dimethyl-p-phenylenediamine → N-[4-(dimethylamino) phenyl]-5-formyl-2,4-dimethyl-1H-pyrrole-3-formamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

1-Ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride (1.074 g, 5.6 mmol), triethylamine (1.12 mL, 8 mmol), 5-formyl-2,4-dimethyl-1H-pyrrole-3-formic acid (0.668 g, 4 mmol) and 1-hydroxybenzotriazole (0.756 g, 5.6 mmol) were added to DMF (10 mL) with stirring at about 0° C. and stirred for 1.5 hrs, then N,N-dimethyl-p-phenylenediamine (1.09 g, 8 mmol) was added. The reaction was stirred at room temperature until completion was indicated by thin layer chromatography (TLC). 1.2 mL of water and 1 mL of saturated salt water were added, and the mixture was extracted with 10% methanol/dichloromethane (25 mL×3), the combined organic phase was washed with saturated salt water (30 mL×3), dried over anhydrous Na2SO4, and the solvent was distilled off under reduced pressure. The residue was then chromatographed (silica gel column chromatography, eluent: methanol:ethyl acetate=1:2) to give 0.682 g (2.4 mmol) of N-[4-(dimethylamino) phenyl]-5-formyl-2,4-dimethyl-1H-pyrrole-3-formamide. Yield 59.9%. 1HNMR (DMSO-d6) δ 10.92 (s, br, 1H, NH), 9.64 (s, 9.34 (s, br, 1H, NH), 7.54-7.52 (d, 2H), 6.77-6.74 (d, 2H), 3.38-2.58 (s, 6H), 2.58-2.56 (m, 3H), 2.55-2.41), (m, 3H).

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