TCMDC_ArylPyrrole

 

Product obtained in 55% yield.

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Scale-up of PMY 8-1 hydrolysis of Ethyl 1-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate to give the desired acid(1-(4-Fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylic acid).



Reaction start time: 14.30 EST 27/10/11
PMY 6-2 (3.05 g, 11.7 mmol, 1 equiv.) was dissolved in EtOH (approx 30 mL) and 20% NaOH (20 mL, approx 8.5 equiv.). Heated to reflux. After 17 hours, reaction was complete by TLC. Reaction allowed to cool to room temperature then in ice. Acidified (pH 1) with 6M HCl. Pale brown precipitate filtered and washed with water. Redissolved in hot acetone (approx 75 mL), cooled to room temperature and water (approx 25 mL) added, then cooled in ice. Brown powder filtered and dried under vacuum (1.49 g, 55%). Mother liquor still contains more mass.

TLC (25% EtOAC/petrol) visualised with UV and vanillin:



NMR:



Risk and Hazard Assessment:
As for Hydrolysis of Ethyl 1-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate (PMY 8-1)

See also:
Hydrolysis of Ethyl 1-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate (PMY 8-2)