Triethylamine → Methyl 3-amino-4-cyano-1H-pyrrole-2-carboxylate

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Reaction Steps

After dissolving dimethyl 2-aminomalonate (25.0 g) in methanol (300 mL), a solution of ethoxymethylene-malononitrile (16.6 g) and triethylamine (15.1 g) in methanol (50 mL) was added. The reaction mixture was stirred at room temperature for 18 hours and then cooled to 0° C., and a mixed solution of 28% sodium methoxide/methanol (31.5 g) and methanol (50 mL) was added dropwise thereto over a period of 10 minutes. The reaction mixture was stirred at room temperature for 49 hours and then cooled to 0° C., and acetic acid (10.3 g) was added. The solvent was distilled off under reduced pressure, ethyl acetate (200 mL) and water (200 mL) were added to the residue and extraction was performed with ethyl acetate. A saturated aqueous sodium bicarbonate solution was added to the organic layer until it exhibited a pH of 8, and extraction was performed with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=1/1) to obtain the title compound (13.7 g, 61%) as a brown solid. The NMR and ESI/MS data for this compound are shown below.

Provenance & Evidence