4-Hydroxybenzoic Acid → 3-[1-(3,5-dimethyl-1H-pyrrol-2-yl)-meth-(Z)-ylidene]-2-oxo-2,3-dihydro-indole-1-carboxylic acid 4-carboxy-phenyl ester

Beteiligte Stoffe

Reaktionsschritte

A reaction mixture of 3-[1-(3,5-dimethyl-1H-pyrrol-2-yl)-meth-(Z)-ylidene]-1-(imidazol-1-ylcarbonyl)-1,3-dihydro-indol-2-one (332 mg, 1.0 mmol), 4-hydroxybenzoic acid (138 mg, 1.0 mmol), and 2 drops of triethylamine in 3.0 mL of THF was stirred at room temperature overnight and concentrated. The residue was then purified on a silica gel column eluting with ethyl acetate-hexane (1:3) and 0.5% of acetic acid in ethyl acetate-dichloromethane (2:1) to afford 150 mg (37%) of 3-[1-(3,5-dimethyl-1H-pyrrol-2-yl)-meth-(Z)-ylidene]-2-oxo-2,3-dihydro-indole-1-carboxylic acid 4-carboxy-phenyl ester. 1H NMR (400 MHz, DMSO-d6) δ 12.65 (s, vbr, 1H, COOH), 12.60 (s, br, 1H, NH-1′), 8.12 (d, J=7.39 Hz, 2H), 7.86-7.88 (m, 1H), 7.64 (s, vbr, 1H), 7.51 (s, 1H, H-vinyl), 7.43 (d, J=7.39 Hz, 2H), 7.21-7.23 (m, 2H), 6.09 (s, br, 1H, H-4′), 2.40 (s, 3H, CH3), and 2.38 (s, 3H, CH3).

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