反应详情

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.

1. temperaturethe solution refluxed for 2 hours
2. customThe solvent was then removed under vacuum
3. additionafter treating the residue with water-ethyl acetate
4. extractionwas extracted several times with ethyl acetate
5. customthe organic extracts were collected
6. washwashed with water
7. dry with materialdried over anhydrous magnesium sulphate
8. filtrationfiltered
9. customthe solvent evaporated
10. customto give a solid, m.p. 61°-64° ex methanol