Water → Methyl 4-bromo-3-methoxythiophene-2-carboxylate

Participants

Reaction Steps

To a solution of 36 g (0.15 mole) of methyl 4-bromo-3-hydroxy-2-thiophenecarboxylate in 300 mL of dimethyl sulfoxide (DMSO) was added 32 g (0.23 mole) of methyl iodide and then 32 g of powdered K2CO3. After 2 hr, the reaction mixture was poured into water and extracted with ether. The organic phase was washed with water (4×200 mL), dried over MgSO4, filtered and concentrated to give 36 g of a colorless solid. 1H NMR (300 MHz, CDCl3): δ 7.4 (s, 1H); 4.0 (s, 3H); 3.9 (s, 3H). Anal. Calc'd for C7H7BrO3S: C, 33.48; H, 2.81; S, 12.77. Found: C, 33.18; H, 2.70; S, 12.49.

Provenance & Evidence