2-Fluoro-4-iodoaniline → 4-(2-Fluoro-4-iodophenylamino)-1-methyl-6-oxo-1,6-dihydropyridazine-3-carboxylic acid

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Reaction Steps

To a solution of 4-chloro-1-methyl-6-oxo-1,6-dihydropyridazine-3-carboxylic acid (350 mg, 1.855 mmol) and 2-fluoro-4-iodoaniline (1.06 g, 4.453 mmol) in tetrahydrofuran (13.3 mL) was sparged with nitrogen for 5 minutes followed by the slow addition of lithium bis(trimethylsilyl)amide, 1.0 M in THF (7.4 mL). The reaction mixture stirred for an additional 4 hours at room temperature. The mixture was quenched with 1 N HCl and concentrated in vacuo. The residue was partitioned between ethyl acetate and 1 N aqueous HCl. The aqueous layer was extracted (3×) with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and evaporated to afford 4-(2-fluoro-4-iodophenylamino)-1-methyl-6-oxo-1,6-dihydropyridazine-3-carboxylic acid (939 mg, 100% yield). 1H NMR (CDCl3): 7.27 (dd, 1H), 7.21 (d, 1H), 6.54 (t, 1H), 4.84 (broad s, 2H), 2.09 (s, 1H), 1.26 (t, 3H); MS (EI) for C12H9N3O3FI: 389 (MH+).

Provenance & Evidence