Ammonia → 3,5-Dibromo-4-cyanothiophene-2-carboxamide

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Reaction Steps

3,5-Dibromo-4-cyanothiophene-2-carboxylic acid (5.90 g, 18.6 mmol) was added to a solution of thionyl chloride (27.1 mL, 371 mmol) in acetonitrile (40.0 mL, 766 mmol). The mixture was refluxed for 30 min then cooled to rt. The solvent was evaporated in vacuo to dryness to yield a lightly yellow solid. Methylene chloride (100 mL, 2000 mmol) was added to dissolve the solid, then the solution was cooled to 0° C. Under a nitrogen atmosphere, a solution of 0.500 M ammonia in 1,4-dioxane (111.5 mL, 55.7 mmol) was slowly added, and the mixture was brought to room temperature for 1 h. The mixture was evaporated in vacuo to give a solid residue. 100 mL of 1N HCl was added and the suspension was stirred for 1 h at room temperature. The solid product was collected by filtration and dried under high vacuum to give product (5.64 g, yield 98%). LCMS: (FA) ES−, 308, 310, 312.

Provenance & Evidence