Sulfuric Acid → 3,5-Dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

4-(4-Fluorophenyl)-2-isopropyl-3,5-dioxo-2,3,4,5-tetrahydro[1,2,4]triazine-6-carboxylic acid. Sulfuric acid (10 mL, 200 mmol) was carefully added to a mixture of 4-(4-fluorophenyl)-2-isopropyl-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6-carboxylic acid ethyl ester (1100 mg, 3.4 mmol) and water (2 mL). The mixture became homogenous after a few minutes. The reaction mixture was stirred at 40° C. overnight, was cooled to rt and was carefully added to ice. The mixture was saturated with solid NaCl and was extracted repeatedly from EtOAc (3×). The combined EtOAc layer was washed with brine, dried over magnesium sulfate, and concentrated to give the product as foam (100%). LCMS m/z=294 (M+1); 1H NMR (Methanol d4) δ: 7.35-7.31 (2 m, 4H), 4.95 (m, 1H), 4.31 (q, 2H, J=7.0 Hz), 1.41 (d, 6H, J=6.6 Hz).

Provenance & Evidence