反应详情

3-(o-Hydroxybenzoyl)propionic acid (14.6 g.) was dissolved in n-butanol (300 ml.) containing 85% potassium hydroxide (10 g.) and the resultant solution was treated with 1-bromopropane (24.6 g.) and the mixture heated at reflux temperature for 4 hours. It was then cooled, filtered to remove potassium bromide and the filtrate washed with cold water. The butanol was evaporated at reduced pressure and the residual oil distilled at 0.3 mm when the fraction b.p. 160°-180° C was collected (16.4 g.). This was dissolved in methanol (50 ml.), treated with 20% sodium hydroxide solution (20 ml.) and heated on the steambath for 30 minutes. The methanol was boiled off and the residue diluted with water (250 ml.) and acidified with hydrochloric acid. The precipitated acid was collected and crystallised from 50% methanol. It had m.p. 77°-79° C (Yield 13.3 g.).

1. temperaturethe mixture heated
2. temperatureat reflux temperature for 4 hours
3. temperatureIt was then cooled
4. filtrationfiltered
5. customto remove potassium bromide
6. washthe filtrate washed with cold water
7. customThe butanol was evaporated at reduced pressure
8. distillationthe residual oil distilled at 0.3 mm when the fraction b.p. 160°-180° C
9. customwas collected (16.4 g.)
10. dissolutionThis was dissolved in methanol (50 ml.)
11. additiontreated with 20% sodium hydroxide solution (20 ml.)
12. temperatureheated on the steambath for 30 minutes
13. additionthe residue diluted with water (250 ml.)
14. customThe precipitated acid was collected
15. customcrystallised from 50% methanol