Sulfuric Acid → Methyl 4-bromo-5-methylthiophene-2-carboxylate

Participants

Reaction Steps

To a stirred solution of 4-bromo-5-methylthiophene-2-carboxylic acid (45 g, 204 mmol) in methanol (225 mL) was added concentrated H2SO4 (4.0 g, 41 mmol). The reaction mixture was heated to reflux overnight, cooled to room temperature, poured into saturated NaHCO3 (800 mL), and left to stir for 30 min. The precipitate was filtered, washed with water, and dried under high-vacuum to afford the title compound. 1H NMR (500 MHz, CDCl3) δ 7.61 (s, 1H); 3.88 (s, 3H); 2.45 (s, 3H). LRMS (APCI) calc'd for (C7H8BrO2S) [M+H]+, 234.9. found 234.9.

Provenance & Evidence