反应详情

A solution of diethyl pyrrole-2,4-dicarboxylate (5.50 g, 29.4 mmol) in tetrahydrofuran (200 ml) was cooled in an ice bath and a suspension of NaH (60%) (6.5 g, 68.6 mmol) in tetrahydro-furan (50 ml) was added in a stream. The reaction flask was warmed to room temperature. After stirring 1 h at room temperature 1,2-dibromoethane (25.2 ml, 294 mmol) was added and the mixture was refluxed for 24 h. Water (50 ml) was added to the reaction flask. The mixture was rotary evaporated to remove tetrahydrofuran. Saturated sodium bicarbonate solution (100 ml) was added to the residue and the resulting solution was extracted with methylene chloride (4×50 ml). The combined organic extracts were dried with anhydrous sodium sulfate. The drying agent was removed by filtration, and the filtrate was rotary evaporated to give a yellow solid. This material was recrystalized from hexane ethyl acetate 80:20 to give 8-2 as a yellow solid.

1. additionwas added in a stream
2. additionwas added
3. temperaturethe mixture was refluxed for 24 h
4. customThe mixture was rotary evaporated
5. customto remove tetrahydrofuran
6. additionSaturated sodium bicarbonate solution (100 ml) was added to the residue
7. extractionthe resulting solution was extracted with methylene chloride (4×50 ml)
8. dry with materialThe combined organic extracts were dried with anhydrous sodium sulfate
9. customThe drying agent was removed by filtration
10. customthe filtrate was rotary evaporated
11. customto give a yellow solid
12. customThis material was recrystalized from hexane ethyl acetate 80:20