Hydrogen Peroxide → 5,5-Dioxo-2-(3-methyl-3-pyridin-4-ylpropionamido)dibenzothiophene

Participants

Reaction Steps

EDAC (0.500 g, 2.6 mmol) was added to a solution of 2-aminodibenzothiophene (0.470 g, 2.4 mmol), 1-hydroxybenzotriazole (0.351 g, 2.6 mmol) and 3-methyl-3-pyridin-4-ylpropanoic acid (Method 7; 0.429 g, 2.6 mmol) in DMF (10 ml). The solution was then stirred at room temperature overnight. The solvent was removed in vacuo and the residue was then shaken in water (50 ml) and DCM (50 ml). The organic layer was separated, washed with brine (50 ml), dried and then evaporated in vacuo to leave a light brown solid. The crude amide was dissolved in a mixture of glacial acetic acid (15 ml) and concentrated sulphuric acid (0.5 ml) at 60° C. and hydrogen peroxide (30 wt. % solution in water, 3 ml) was added. The mixture was stirred at 60° C. for 2 hours and left to cool to room temperature overnight. The mixture was poured into water (50 ml) and made basic by the addition of potassium carbonate. The mixture was extracted into DCM (50 ml), the organic layer was separated and washed with brine (50 ml), dried and evaporated in vacuo to leave a light brown solid. The crude product was triturated with methanol (10 ml) to leave a pale yellow solid (0.496 g). NMR: 10.47 (s, 1H), 8.3 (d, 1H), 7.9 (m, 3H), 7.75 (t, 1H), 7.65 (m, 2H), 3.3 (m, 1H), 2.7 (m, 2H), 1.3 (d, 3H); m/z 379.

Provenance & Evidence