Water → 2-(4-Nitro-phenyl)-1H-imidazo[4,5-b]pyridine-6-carboxylic acid

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Reaction Steps

To a suspension of 6-Amino-5-(4-nitro-benzoylamino)-nicotinic acid methyl ester (5) (4.05 g, 13 mmol) in ethylene glycol (300 ml) was added conc. HCl (20 drops) and the mixture heated at 160 C for 5 h. TLC in DCM/MeOH (19:1) indicates the absence of starting material. The solution was cooled and poured into H2O and the solid collected by filtration and air-dried. 1H NMR (500 MHz, DMSO-d6) δ14.08 (br s, 1H), 8.97 (s, 1H), 8.51 (br s, 1H), 8.49 (d, J=8.7 Hz, 2H), 8.43 (d, J=8.7 Hz, 2H), 3.92 (s, 3H). EIMS m/z M−1 297.3

Provenance & Evidence