Sodium Hydroxide → 5-(2,4-Dichlorobenzoyl)-1,4-dimethyl-1H-pyrrole-2-acetic acid

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Reaction Steps

A solution of 2.38 mL (1.1 eq) of 1N NaOH was added dropwise to a refluxing solution of 76.89 g (0.217 mole) of ethyl 5-(2,4-dichlorobenzoyl)-1,4-dimethyl-1H-pyrrole-2-acetate (3) in 750 mL absolute ethanol. The mixture was heated under reflux for 20 minutes. The reaction was poured into 3N HCl/ice and extracted three times with diethyl ether. The organics were washed with water (twice), brine, and dried (MgSO4). Evaporation of the solvent in vacuo gave a tan oil which was crystallized from acetonitrile to give 63.05 g of product: mp 140-143° C.; mass spectrum (Cl—CH4) m/z=326 (M+1); NMR 300 MHz (Me2SO-d6) d 7.8 (s, 1H); 7.6 (m, 1H); 7.4 (m, 1H); 6.0 (s, 1H); 3.8 (s, 3H); 3.75 (s, 2H); 1.45 (s, 3H). Anal Calcd for C15H13Cl2NO3: C, 55.24; H, 4.02; N, 4.29. Found: C, 55.47; H, 3.84; N, 4.29.

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