反应详情

温度

60 °C

3,4-Diethylpyrrole (2A, FIG. 2A)28 (0.6 g, 4.9 mmol), benzyl 5-(acetoxymethyl)-3-methyl-4-ethyl-pyrrole-2-carboxylate (2B, FIG. 2A)29 (2.5 g, 7.9 mmol), and p-toluenesulfonic acid (0.15 g) were dissolved in 60 mL of absolute ethanol and heated at 60° C. for 8 h under nitrogen. The resulting suspension was reduced in volume to 30 mL and placed in the freezer for several hours. The product was then collected by filtration, washed with a small amount of cold ethanol, and recrystallized from dichloromethane-ethanol to afford a white powder (2.07 g, 82%): mp 211° C. NMR spectra and high resolution mass spectral data were obtained as described and are reported 13a.

1. waitplaced in the freezer for several hours
2. filtrationThe product was then collected by filtration
3. washwashed with a small amount of cold ethanol
4. customrecrystallized from dichloromethane-ethanol