反应详情

1-(1-Methyl-1H-pyrrol-2-yl)-ethanone (4.00 g, 32.48 mmol) in dry methylene chloride (30 mL) was cooled to −78° C. under nitrogen. Chlorosulfonyl isocyanate (2.8 mL, 32.5 mmol) was added dropwise, and the mixture allowed to warm to room temperature over 1 h. The reaction was cooled down to −78° C. and dimethylformamide (8 mL) was added. The reaction was allowed to warm up to room temperature (2 h) and was then poured into a 1 N sodium carbonate solution, which was extracted with methylene chloride. The organic layers were washed with water, dried (anhydrous MgSO4) and evaporated. The residue was then purified by silica gel column chromatography (ethyl acetate:hexanes 1:5 to 1:3) to afford 5-acetyl-1-methyl-1H-pyrrole-3-carbonitrile (1.63 g, 34%), which was used without further characterization.

1. temperatureThe reaction was cooled down to −78° C.
2. temperatureto warm up to room temperature (2 h)
3. extractionwas extracted with methylene chloride
4. washThe organic layers were washed with water
5. dry with materialdried (anhydrous MgSO4)
6. customevaporated
7. customThe residue was then purified by silica gel column chromatography (ethyl acetate:hexanes 1:5 to 1:3)