2-Nitro-1-phenylpropene → 1H-Pyrrole-2-carboxylic acid, 4-methyl-3-phenyl-, ethyl ester

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Reaction Steps

1,8-Diazabicyclo[5.4.0]undec-7-ene (3.70 g, 24.6 mmol) was added dropwise to a stirred solution of ethyl isocyanoacetate (1.50 g, 13.3 mmol) and 2-nitro-3-phenyl-2-propene (2.0 g, 12.3 mmol) in a mixture of tetrahydrofuran (15 mL) and iso-propanol (5 mL) at between 10 and 20° C. The reaction mixture was stirred at room temperature for 4 h. Excess tetrahydrofuran was removed in vacuo, water (15 mL) was added to the residue and the mixture was extracted with diethyl ether (3×25 mL). The combined organic phases were washed with brine (2×15 mL), dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford ethyl 4-methyl-3-phenyl-1H-pyrrole-2-carboxylate (2.5 g, 90%) as an oil.

Provenance & Evidence