反应详情

A mixture of 2-amino-4-(2-methoxyphenyl)thiophene-3-carboxylic acid ethyl ester (2 mmol, Example 17, Part B) and phthalic anhydride (2.2 mmol) in glacial acetic acid (20 mL) is heated at reflux overnight. After cooling to room temperature, the acetic acid is removed in vacuo and the residue triturated with petroleum ether. The crude product is collected by filtration, suspended in acetyl chloride (5 mL), and heated to reflux for one hour. After removing the solvent in vacuo, the residue is 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 affords the desired product.

1. temperatureis heated
2. temperatureat reflux overnight
3. customthe acetic acid is removed in vacuo
4. customthe residue triturated with petroleum ether
5. filtrationThe crude product is collected by filtration
6. temperatureheated
7. temperatureto reflux for one hour
8. customAfter removing the solvent in vacuo
9. dissolutionthe residue is 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