Dimethylformamide → N,N,N',N'-Tetramethylazodicarboxamide

Participants

Reaction Steps

To a solution of 4,4'-diaminostilbene-2,2'-disulfonic acid disodium salt (2.5 mmol, 1.036 g) in DMF (170 mL) a solution of 8-hydroxyquinoline-7-carboxylic acid (5.0mmol, 0.946 g) in DMF (140 mL) was added. To the mixture, 1-hydroxybenzotriazole (HBT) (6.0 mmol, 0.811 g) was added followed by 1,3-dicyclohexylcarbocilmide (DCC) (12.0 mmol, 2.476 g). The reaction mixture was stirred at room temperature for 6 days. Then, the solution was concentrated under reduced pressure. The precipitate was filtered off. The filtrate was evaporated in vacuo. To the residue, water and methanol (1:4) were added, and the pH was adjusted to 8. The insoluble material was filtered off, and the filtrate was evaporated under reduced pressure. The residue was extracted with choloroform (3×). The solid was collected by filtration, and treated with methanol. Insoluble material was filtered off and dried to give 0.8 g of pure, desired diamide. The methanol solution was used for fractionation on a Sephadex LH-20 column, with the eluent being methanol. This method allowed for the separation of an additional 0.59 g pure diamide (yield 73.5%) and traces of monoamide.

Provenance & Evidence