p-Toluenesulfonic acid → 2,5-Bis(5-benzyloxycarbonyl-3-ethyl-4-methylpyrrol-2-ylmethyl)-3,4-diethylpyrrole

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Reaction Conditions

Reaction Steps

3,4-Diethylpyrrole (2A, FIG. 2)28 (0.6, 4.9 mmol), benzyl 5-(acetoxymethyl)-3-methyl-4-ethyl-pyrrole-2-carboxylate (2B, FIG. 2)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.

Provenance & Evidence