反应详情

EtOH (30 mL) was added to 2,5-dicarbethoxy-3,4-dihydroxythiophene (1 g). A solution of NaOH (4.0 g) in H2O (20 mL) was added and refluxed under N for 20 h. Upon cooling to ambient temperature the EtOH was removed by distillation and the residue was redissolved in H2O then acidified with 15% HClaq when a white ppt was obtained This product was collected by filtration and washed with cold H2O then crystallized from dilute MeOH to give colorless needles.

1. temperaturerefluxed under N for 20 h
2. customwas removed by distillation
3. dissolutionthe residue was redissolved in H2O
4. customwas obtained This product
5. filtrationwas collected by filtration
6. washwashed with cold H2O
7. customthen crystallized from dilute MeOH
8. customto give colorless needles