Iodoethane → 5-Ethyl-1H-pyrrole-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

Iodoethane (3.99 g, 25.61 mmol) was added to a solution of 1-isocyanomethanesulfonyl-4-methyl-benzene (5 g, 25.61 mmol) in anhydrous THF (20 ml). The mixture was cooled to −78° C. and potassium tert-butoxide (31 ml of a 1 M solution in THF, 31 mmol) was added dropwise over 15 minutes. The mixture was warmed to room temperature over 1 h. Water (50 ml) was added and the solution was extracted with diethylether and dried over Na2SO4 and evaporated to dryness. The resulting brown oily material was used without purification. The resulting 1-(1-Isocyano-propane-1-sulfonyl)-4-methyl-benzene (4.29 g, 19.05 mmol) and acrylonitrile (1.26 ml, 19.05 mmol) were stirred in anhydrous THF (20 ml). The mixture was cooled to 0° C. and potassium tert-butoxide in THF (38.1 ml, 38.1 mmol) was added dropwise. The mixture was heated to reflux for 2 h then left at room temperature overnight, and then concentrated in vacuo. EtOAc (30 ml) was added to the brown solid and the mixture was stirred at room temperature for a few hours, filtered and the solid washed well with EtOAc. The EtOAc solution was concentrated in vacuo and purified by flash chromatography eluting with EtOAc/n-hexanes mixture: 3:2 to afford the title compound. (0.856 g).

Provenance & Evidence