Methanol → Methyl 4-bromo-1H-pyrrole-2-carboxylate

To a solution of Example 1B (20 g, 68 mmol) in methanol (100 mL), a solution of NaOMe (1M in MeOH, 34 mL, 34 mmol) was added slowly. This mixture was then stirred at ambient temperature for 1 h after which it was diluted with water (300 mL) and the organic layer was separated. The aqueous phase was extracted with CH2Cl2 and the combined organic layer and extracts were washed with water (2×50 mL), dried (MgSO4) and evaporated under reduced pressure. Recrystallization of the residue from hexane gave 4-Bromo-2-methoxycarbonylpyrrole (Example 1C, 12 g, 85%) as a white solid. LC-MS, [M−H]+=203. 1H NMR (DMSO-d6, 400 MHz): δ 12.31 (brs, 1H), 7.16 (s, 1H), 6.81 (s, 1H), 3.75 (s, 3H).