Malonic Acid → 2,2'-methylenebis(1h-benzimidazole)

Participants

Reaction Steps

To a flask were added 5 g of 1,2-phenylene diamine, 2.4 g of malonic acid, and 20 g of polyphosphoric acid. The mixture was heated to 180 C under nitrogen for 4 hours, and then cooled to 150 C. After the addition of 40 ml of water, the mixture was cooled to 22 C and neutralized with aqueous ammonium hydroxide. The solid was filtered and washed with water. After triturating the product in 200 ml of hot acetonitrile, the mixture was cooled to 22 C, filtered, washed with acetonitrile, and dried resulting in 2.7 g of a gray solid.

Provenance & Evidence