2-Pyrazinecarboxylic acid → Pyrazinamide

Participants

Reaction Conditions

Reaction Steps

Diethylaniline (0.33 μL, 2.1 μmol, 1.1 equiv) was added in one portion to a stirred solution of the amine (1.0 mg, 1.9 μmol, 1 equiv) in THF (0.2 mL) at 0° C. under an argon atmosphere and the solution was stirred for 5 min. 2-Pyrazinecarboxylic acid (0.31 mg, 2.5 μmol, 1.3 equiv), 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (0.48 mg, 2.5 μmol, 1.3 equiv) and 1-hydroxybenzotriazole (0.31 mg, 2.3 μmol, 1.2 equiv) were then added separately, each in one portion, to the above solution at 0° C. The reaction mixture was warmed to 23° C. over 17 h 40 min, then was quenched with saturated aqueous ammonium chloride solution (3 mL). The mixture was diluted with ethyl acetate (10 mL) and the layers were separated. The aqueous layer was extracted with ethyl acetate (10 mL) and the combined organic layer was dried over sodium sulfate. Concentration in vacuo left a white solid, which was purified by flash column chromatography (80% ethyl acetate-hexanes) to give the pyrazine-2-carboxylic acid amide derivative (1.1 mg, 92%) as a white solid.

Provenance & Evidence