Dimethyl Sulfate → Dimethyl 3-methoxy-4-methyl-2,5-thiophene dicarboxylate

Participants

Reaction Steps

A solution of dimethyl 4-hydroxy-3-methyl-2,5-thiophene dicarboxylate (4.26 g) in acetone (100 ml) containing anhydrous potassium carbonate (2.34 g) was stirred for 1 hour at room temperature. Dimethyl sulphate (1.62 ml) was added and the solution refluxed for 2 hours. The solvent was then removed under vacuum and, after treating the residue with water-ethyl acetate, was extracted several times with ethyl acetate; the organic extracts were collected, washed with water, dried over anhydrous magnesium sulphate, filtered and the solvent evaporated to give a solid, m.p. 61°-64° ex methanol.

Provenance & Evidence