反应详情

温度

100 °C

A mixture of methyl 3,4-diamino-5-methylthiophene-2-carboxylate (1.0 g) in pentafluoropropionic acid (8.9 g) was stirred at 100° C. for 6 hr. The reaction solution was concentrated to dryness and the residue was suspensed in water. The mixture was made basic with aqueous solution of K2CO3, followed by extraction with ethyl acetate. The organic layer was washed with water, dried and concentrated to dryness. The residue was purified by silica gel column chromatography to give crystals. Recrystallization from isopropyl ether-hexane gave colorless plates (0.86 g, 51%). m.p. 156°-157° C.

1. concentrationThe reaction solution was concentrated to dryness
2. extractionfollowed by extraction with ethyl acetate
3. washThe organic layer was washed with water
4. customdried
5. concentrationconcentrated to dryness
6. customThe residue was purified by silica gel column chromatography
7. customto give crystals
8. customRecrystallization from isopropyl ether-hexane
9. customgave colorless plates (0.86 g, 51%)