反应详情

1-Benzyl-5-methyl-1H-pyrrole-2-carbaldehyde, 4: POCl3 (23.46 mL, 246 mmol) was added dropwise to a stirred N,N-dimethyformamide (204 mL) at 0° C. After addition the mixture was stirred for additional 90 minutes. To the mixture was added dropwise the solution of 1-benzyl-2-methyl-1H-pyrrole, 3 (2.71 g, 45 mmol) in tetrahydrofuran (1150 mL). The reaction mixture was allowed to be stirred for 18 h from 0° C. to room temperature. The mixture was concentrated and redissolved in ethyl acetate (2 L). The mixture was washed with saturated Na2CO3 (2×500 mL). The Na2CO3 solution was extracted with ethyl acetate (7×1 L). The organic layers were combined and concentrated. The crude product was purified by silica gel chromatography (hexane to hexane:ethyl acetate, 7:1) to afford 1-benzyl-5-methyl-1H-pyrrole-2-carbaldehyde, 4 as a light yellow liquid. Yield: 30.8 g (81%).

1. additionAfter addition the mixture
2. stirringto be stirred for 18 h from 0° C. to room temperature
3. concentrationThe mixture was concentrated
4. dissolutionredissolved in ethyl acetate (2 L)
5. washThe mixture was washed with saturated Na2CO3 (2×500 mL)
6. extractionThe Na2CO3 solution was extracted with ethyl acetate (7×1 L)
7. concentrationconcentrated
8. customThe crude product was purified by silica gel chromatography (hexane to hexane:ethyl acetate, 7:1)