反应详情

To 1.0 g (3.7 mmol) of methyl 4-bromo-5-methylthiothiophene-2-carboxylate (as prepared in Example 241, step (a) dissolved in 25 ml of MeOH was added 450 mg of NaOH dissolved in 10 ml of H2O. The reaction was stirred for 5 hours at room temperature, and then the solvents were removed under vacuum. The residue of the reaction was extracted with ethyl acetate (2×50 mL) and 1N HCl. The organic layer was collected, dried (Na2SO4), filtered and concentrated under vacuum to yield 833 mg (89%) of 4-bromo-5-methylthiothiophene-2-carboxylic acid as a white solid.

1. customthe solvents were removed under vacuum
2. extractionThe residue of the reaction was extracted with ethyl acetate (2×50 mL) and 1N HCl
3. customThe organic layer was collected
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated under vacuum