反应详情

A mixture of 2-amino-4-phenylthiophene-3-carboxylic acid ethyl ester (2 mmol, Example 1, Part B) and phthalic anhydride (2.2 mmol) in glacial acetic acid (20 mL) was heated at reflux overnight. After cooling to room temperature, the acetic acid was removed in vacuo and the residue triturated with petroleum ether. The crude product was collected by filtration, suspended in acetyl chloride (5 mL), and heated to reflux for one hour. After removing the solvent in vacuo, the residue was dissolved in ethyl acetate (30 mL), washed sequentially with 5% aqueous NaHCO3 (10 mL), water (10 mL), brine (10 mL), dried (Na2SO4), filtered, and concentrated in vacuo. Recrystallization from petroleum ether afforded the desired product as a yellow solid in 70% yield.

1. temperaturewas heated
2. temperatureat reflux overnight
3. customthe acetic acid was removed in vacuo
4. customthe residue triturated with petroleum ether
5. filtrationThe crude product was collected by filtration
6. temperatureheated
7. temperatureto reflux for one hour
8. customAfter removing the solvent in vacuo
9. dissolutionthe residue was dissolved in ethyl acetate (30 mL)
10. washwashed sequentially with 5% aqueous NaHCO3 (10 mL), water (10 mL), brine (10 mL)
11. dry with materialdried (Na2SO4)
12. filtrationfiltered
13. concentrationconcentrated in vacuo
14. customRecrystallization from petroleum ether