反应详情

A solution of 7.3 g of potassium hydroxide dissolved in 20 ml of water was added to 200 ml of an ethanol solution containing 24.2 g of 3-(5-bromobenzo[b]thien-2-yl)-2-ethoxycarbonyl-2-(4-methoxyphenyl)propionate obtained in the above step a), and the thus prepared mixture was stirred for 4 days. The resulting reaction solution was poured into cooled dilute hydrochloric acid to collect precipitated crystals by filtration. The thus collected crystals were dissolved in ethyl acetate, and then dried. After distilling off the solvent, the resulting residue was dissolved in 200 ml of ethanol, mixed With 3 ml of concentrated sulfuric acid, and then refluxed under heating for 2 hours. After cooling, the resulting reaction solution was concentrated, mixed with chloroform, washed with water, and then dried. After distilling off the solvent, the resulting residue was purified by subjecting it to silica gel column chromatography using chloroform as an eluant, thereby obtaining 20 g of ethyl 3-(5-bromobenzo[b]thien-2-yl)-2-(4-methoxyphenyl)propionate.

1. customobtained in the above step a), and the thus prepared mixture
2. customThe resulting reaction solution
3. additionwas poured
4. customto collect
5. customprecipitated crystals
6. filtrationby filtration
7. dissolutionThe thus collected crystals were dissolved in ethyl acetate
8. customdried
9. distillationAfter distilling off the solvent
10. dissolutionthe resulting residue was dissolved in 200 ml of ethanol
11. additionmixed With 3 ml of concentrated sulfuric acid
12. temperaturerefluxed
13. temperatureunder heating for 2 hours
14. temperatureAfter cooling
15. customthe resulting reaction solution
16. concentrationwas concentrated
17. additionmixed with chloroform
18. washwashed with water
19. customdried
20. distillationAfter distilling off the solvent
21. customthe resulting residue was purified