Ethyl trans-crotonate → Ethyl 4-methyl-1h-pyrrole-3-carboxylate

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Reaction Steps

Based on D. O. Cheng, T. L. Bowman, E. LeGoff, J. Heterocyclic Chem. 13, 1145 (1976), 3,4-dimethylpyrrole was synthesized starting from p-toluol-sulfonylmethyliso-cyanide and crotonic-acid-ethyl-ester. The dimethyl compound was quickly obtained after reduction of the intermediary 3-(ethoxycarbonyl)-4-methylpyrrole, but at only 18% total yield. The material had a melting point of 25°-28° C. H-NMR (CDCl3): 2.04 (s, 6H), 6.50 (d, 2H), 7.33 (s br, 1H).

Provenance & Evidence