Carbon Dioxide → 3-(4-Methylphenyl)-1H-pyrrole-2,5-dione

Participants

Reaction Steps

A 53.6 g portion of p-toluidine was dissolved in a mixture of 150 ml of 12N-hydrochloric acid and 100 ml of water, cooled in an ice-salt bath. A 100 g portion of ice was added and then a solution of 35 g of sodium nitrite in 80 ml of water was added dropwise with stirring over 1/2 hour. A solution of 48.5 g of maleimide in 400 ml of acetone was then added in one portion and the mixture was cooled in an ice-salt bath with 20 g of dry ice added to the reaction mixture. A 125 g portion of sodium acetate was added to achieve pH 3. Ten minutes later 5.0 g of cupric chloride dihydrate was added. The mixture was filtered and the filtrate was allowed to stand 64 hours. The solid was collected, added to 30 ml of 2,6-lutidine and heated on a steam bath for 1/2 hour, then poured into one liter of water and filtered. The filtrate produced pale yellow crystals which were collected, giving 2-(p-tolyl)maleimide.

Provenance & Evidence