Sulfuric Acid → 4-{[2-(4-Bromo-3-methylphenylcarbamoyl)thiophen-3-ylamino]methyl}pyridine-2-carboxylic acid methylamide

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Reaction Conditions

Reaction Steps

To a stirred solution of N-(4-bromo-3-methylphenyl) 3-aminothiophene-2-carboxamide (1 equiv, prepared as described above for EXAMPLE 1, part 1, using 4-bromo-3-methylaniline instead of 4-trifluoromethoxyaniline) in THF at 0° C. in an open flask, was added 2-(N-methylcarbamoyl)pyridine-4-carboxaldehyde (prepared as described in International Patent Publication No. WO 01/23375) (1.1 equiv) in THF and 4M H2SO4 (0.1 equiv) and the mixture was stirred for 30 min at 0° C. Sodium borohydride (1 equiv) was added portionwise and the mixture was allowed to warm to RT and stirred for 2 h. Water was then added, the mixture was basified to pH 12 with 2M sodium hydroxide solution, and the resulting product was extracted into ethyl acetate. The combined extracts were washed with water followed by brine, dried (MgSO4), filtered and concentrated in vacuo to afford a yellow semisolid, which was purified by column chromatography eluting with a 95:5 mixture of hexane:ethyl acetate increasing gradually to a 50:50 mixture. MS (ES+): 459, 461 [MH+]

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