2,5-Hexanedione → 1,3-dimethyl 5-(2,5-dimethyl-1H-pyrrol-1-yl)benzene-1,3-dicarboxylate

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Reaction Steps

To a solution of dimethyl 5-aminoisophthalate (8, 10.5 g, 50 mmol) in toluene (50 mL) was added acetonylacetone (6.18 mL, 52.5 mmol) and p-TsOH (95 mg, 0.5 mmol). The reaction mixture was heated in a Dean-Stark apparatus under reflux for 12 h. After cooling to room temperature, the mixture was concentrated with a rotary evaporator, and the resulting brown oil was purified by flash column chromatography (EtOAc/hexanes, 1:19-1:9) to give 9 (13.2 g, 46 mmol, 92%) as a white solid: 1H NMR (500 MHz, CDCl3) δ 2.05 (s, 6H), 3.99 (s, 6H), 5.95 (s, 2H), 8.11 (s, 2H), 8.74 (s, 1H); 13C NMR (125 MHz, CDCl3) δ 13.3, 52.9, 106.8, 128.9, 130.0, 132.0, 133.6, 139.9, 165.7; LC-MS (M +H+) calcd for C16H18NO4 288, found 288.

Provenance & Evidence