TCMDC_ArylPyrrole

 

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: 16.45 EST 22/09/11
PMY 6-1 (1.05 g, 4.0 mmol, 1 equiv.) was dissolved in EtOH (approx 30 mL) and 20% NaOH (20 mL, approx 25 equiv.). Heated to reflux. After 15 hours, reaction was complete by TLC. Reaction allowed to cool to room temperature then in ice. Acidified (pH 2) with 2M HCl. Extracted with EtOAc (3 × 40 mL). Combined extracts washed with water (3 × 30 mL) and brine then dried (MgSO₄) and concentrated under reduced pressure to a red/brown solid. Recrystallised (acetone/water) to give a white powder (608 mg, 65%). mpt: 241-242 °C.)

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


NMR:



IR:


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