Hydrochloric Acid → 3-(4-bromophenyl)-2,5-dihydro-1H-pyrrole-2,5-dione

Participants

Reaction Conditions

Reaction Steps

A solution of hydrochloric acid (37%, 13 mL) in water (5.5 mL) was added to 4-bromoaniline (7.48 g, 43.52 mmol) at r.t. with vigorous stirring and the formed precipitate was allowed to stir for 30 min. The reaction mixture was cooled to 0° C. and a solution of sodium nitrite (3.30 g, 47.87 mmol) in water (9 mL) was added dropwise. At the end of diazotization, a clear yellow solution was obtained. Maleimide (8.45 g, 87.05 mmol) in acetone (35 mL) was added dropwise at 0° C. and then the pH of the solution was adjusted to 3-3.5 by adding sodium acetate. CuCl2 (0.88 g, 6.57 mmol) was added to the vigorously stirred mixture. The reaction mixture was stirred at 0° C. for 1 h and overnight at r.t. After completion of the reaction as confirmed by TLC, solvents were removed in vacuo to afford the crude compound, which was purified by column chromatography (silica gel, 4:6 EtOAc:Pet. ether) to afford the title compound as a yellow solid (5.8 g, 57%).

Provenance & Evidence