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

Temperature

-78 °C

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).

1. temperatureThe mixture was warmed to room temperature over 1 h
2. extractionthe solution was extracted with diethylether
3. dry with materialdried over Na2SO4
4. customevaporated to dryness
5. customThe resulting brown oily material was used without purification
6. temperatureThe mixture was cooled to 0° C.
7. temperatureThe mixture was heated
8. temperatureto reflux for 2 h
9. concentrationconcentrated in vacuo
10. additionEtOAc (30 ml) was added to the brown solid
11. filtrationfiltered
12. washthe solid washed well with EtOAc
13. concentrationThe EtOAc solution was concentrated in vacuo
14. custompurified by flash chromatography
15. washeluting with EtOAc/n-hexanes mixture

ORD record

ord-dc818050001b424d9c92613eea118063

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07709503B2