反应详情

A solution (0.5 M) of 5-methyl-4-nitrothiophene-2-carboxylic acid in methanol was treated with sulfuric acid (3.5 eq.). The reaction mixture was heated to reflux for 48 h. After cooling down, solvent was evaporated giving a residue that was dissolved in AcOEt and water was added. The organic phase was separated and the aqueous layer was extracted with AcOEt. The combined organic phase was washed sequentially with aqueous NaHCO3 (saturated solution) and brine, then dried and concentrated giving the title compound (69%) as solid.

1. temperatureThe reaction mixture was heated
2. temperatureto reflux for 48 h
3. temperatureAfter cooling down
4. customsolvent was evaporated
5. customgiving a residue that
6. customThe organic phase was separated
7. extractionthe aqueous layer was extracted with AcOEt
8. washThe combined organic phase was washed sequentially with aqueous NaHCO3 (saturated solution) and brine
9. customdried
10. concentrationconcentrated