Sodium Bicarbonate → 4-(4-{[(3,4-Dichloro-5-methyl-1H-pyrrol-2-yl)carbonyl]amino}piperidin-1-yl)quinoline-2-carboxylic acid

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Reaction Steps

tert-Butyl 4-{[(3,4-dichloro-5-methyl-1H-pyrrol-2-yl)carbonyl]amino}piperidine-1-carboxylate (Intermediate 2) (280 mg, 0.74 mmol) was suspended in 5 ml of 4.0 M HCl in dioxane and stirred for 2 h, then evaporated in vacuo to give a brown solid, which was dissolved in 20 ml of DMF. 4-Bromoquinoline-2-carboxylic acid (188 mg, 0.74 mmol) (prepared via the procedure of Y Kato, et. al., Tetrahedron Lett 2001, 42:4849-51), and sodium bicarbonate (554 mg, 6.6 mmol) were added and the resulting solution was heated under a nitrogen atmosphere with stirring for 20 h. Upon cooling to ambient temperature, the reaction was diluted with 25 ml of water, adjusted to pH 4 using concentrated HCl, filtered and the filtrate extracted with chloroform (2×25 ml). The combined organic extract was dried over sodium sulfate and concentrated in vacuo to a yellow solid, which was suspended in 10 ml of MeOH and collected by suction filtration, to afford the title compound as a yellow solid (64 mg).

Provenance & Evidence