Dimethylformamide → 2-cyclopropyl-1H-indole

Participants

Reaction Steps

0.54 g of copper(I) iodide is added to a solution of 0.42 g of 2-cyclopropylethynylphenylamine in 20 ml of N,N-dimethylformamide under argon. The reaction mixture is refluxed for 2 hours, and is then concentrated to dryness under reduced pressure. The residue is taken up in a mixture of 200 ml of water and 100 ml of dichloromethane, filtered through Celite®, and then separated by settling out. The organic phase is separated and the aqueous phase is extracted with 50 ml of dichloromethane. The organic phases are combined, washed with 100 ml of water, dried over anhydrous magnesium sulfate, filtered, and then concentrated to dryness under reduced pressure. The residue is purified on a 50 g column of 20-45 μm silica, elution being carried out with a 50/50 v/v cyclohexane/dichloromethane mixture. 0.18 g of 2-cyclopropylindole is thus obtained in the form of a yellow solid, the characteristics of which are the following:

Provenance & Evidence