反应详情

温度

25 °C

N,N-dimethyl propionamide (3.24 g, 3.52 ml, 32.08 mmol) was cooled at 0-5° C. and and to this was added POCl3 (4.9 g, 2.9 ml, 32.08 mmol) slowly in a dropwise manner. The resulting mixture was then stirred at room temperature (about 25° C.) for 20 minutes. The reaction mixture was then diluted with 1,2-dichloroethane (60 ml) and cooled to 0° C. To the cooled reaction mixture was then added a solution of 2-(4-chlorophenyl)-1,3-dimethyl-1H-pyrrole (prepared according to the procedure given in Tetrahedron Letters 46 (2005) 4539-4542, 6.0 g, 29.17 mmol) in 1,2-dichloroethane (60 ml) dropwise. The reaction mixture was then heated to reflux for 30 minutes. The progress of the reaction was monitored by TLC. The mixture so obtained was allowed to cool to room temperature and was diluted with aqueous solution of sodium acetate trihydrate (21.8 g, 160.4 mmol in 45 ml water). The mixture so obtained was further heated to reflux for 30 minutes, two layers were separated. The aqueous layer was extracted with dichloromethane (3×100 ml). The combined organic layer was washed with water (1×100 ml) and dried over anhydrous Na2SO4. The solvent from the reaction mixture was evaporated under reduced pressure to obtain a crude product. This crude product was purified by column chromatography over silica gel (100-200 mesh) using 4-6% ethyl acetate in hexanes as an eluent to obtain the title compound (6.55 g, 85.8%)

1. temperaturecooled to 0° C
2. customTo the cooled reaction mixture
3. customprepared
4. temperatureThe reaction mixture was then heated
5. temperatureto reflux for 30 minutes
6. customThe mixture so obtained
7. temperatureto cool to room temperature
8. customThe mixture so obtained
9. temperaturewas further heated
10. temperatureto reflux for 30 minutes
11. customtwo layers were separated
12. extractionThe aqueous layer was extracted with dichloromethane (3×100 ml)
13. washThe combined organic layer was washed with water (1×100 ml)
14. dry with materialdried over anhydrous Na2SO4
15. customThe solvent from the reaction mixture was evaporated under reduced pressure
16. customto obtain a crude product
17. customThis crude product was purified by column chromatography over silica gel (100-200 mesh)