Ammonia → 5-(Piperazin-1-yl)benzofuran-2-carboxamide

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Reaction Steps

Methyl 5-(1-piperazinyl)benzofuran-2-carboxylate (37 g) was added to saturated methanolic ammonia solution (1850 ml) at 25-30° C., the mixture was stirred for 6 to 16 hours at the same temperature. The reaction mass was distilled under vacuum to remove the solvent after completion of the reaction. Water (148 ml) was added to the resulting residue, followed by adjusting the pH to 2-4 with concentrated HCl and then filtering the aqueous layer. The pH of the resulting aqueous layer was adjusted to 9-10 with ammonium hydroxide solution. The separated solid was filtered, washed with water (100 ml) and then dried to produce 25.5 g of 5-(1-piperazinyl)benzofuran-2-carboxamide (Purity by HPLC: 99%; Yield: 73.1%).

Provenance & Evidence