A mixture of ethyl 5-bromo-1,4-dimethyl-1H-pyrrole-3-carboxylate (246 mg, 1.0 mmol), 4-fluorophenyl-boronic acid (210 mg, 1.5 mmol), Na2CO3 (320 mg, 3.0 mmol) and Pd(PPh3)4 (116 mg, 0.10 mmol) in DMF/H2O (10:1, 10 mL) was sparged with nitrogen for 10 min. The reaction vial was sealed and heated at 110° C. with stirring. After 18 h, the reaction mixture was diluted with DCM and then filtered. The filtrate was concentrated under reduced pressure and then purified by column chromatography, eluting with EtOAc-Hex (0:100 to 50:50), to give 1,4-dimethyl-5-(4-fluorophenyl)-1H-pyrrole-3-carboxylic acid ethyl ester (252 mg, 96%) as a pale yellow solid. 1H-NMR (CDCl3): δ 7.30 (1H, s), 7.26-7.20 (2H, m), 7.15-7.10 (2H, m), 4.28 (2H, q), 3.48 (3H, s), 2.20 (3H, s), 1.36 (3H, t). MS (ESI): 262 (MH+). The title compound was prepared from 1,4-dimethyl-5-(4-fluorophenyl)-1H-pyrrole-3-carboxylic acid ethyl ester in a manner similar to that described for Examples 16C-D.
