Dihydrocoumarin → 4-Hydroxy-1-indanone

Temperature

200 °C

Dihydrocoumarin (10.5 grams; 0.07 mole) and anhydrous aluminum trichloride powder (19.0 grams; 0.14 mole) were charged into a 300 ml glass reaction flask equipped with a mechanical stirrer, thermometer and gas inlet tube. The flask was purged with nitrogen gas and the reaction mixture was slowly heated to a temperature of 200° with stirring. Heating at 200° C. and stirring were continued for a period of one hour. After this time the reaction mixture was cooled in an ice bath and aqueous hydrochloric acid (50 ml conc. HCl+50 ml H2O) was added dropwise. After the addition was completed, stirring was continued at room temperature for a period of about 1 hour. After this time the reaction mixture was transferred into a separatory funnel and extracted with methylene chloride. During extraction a solid precipitate formed. The precipitate was recovered by filtration. The remaining aqueous phase was then extracted with ether and the ether extract was combined with the methylene chloride extract. The extracts were then dried over anhydrous magnesium sulfate filtered and stripped of solvents leaving a solid residue. This residue was combined with the precipitate. This material was combined with the product obtained from a repeat of the foregoing procedure and the combined products were recrystallized from methanol. The resulting product was dried under vacuum at 80° C. for about 8 hours to yield the desired product 4-hydroxyindan-1-one having a melt point of 243° C.

1. customequipped with a mechanical stirrer
2. customThe flask was purged with nitrogen gas
3. temperaturethe reaction mixture was slowly heated to a temperature of 200°
4. stirringstirring
5. temperatureAfter this time the reaction mixture was cooled in an ice bath
6. additionaqueous hydrochloric acid (50 ml conc. HCl+50 ml H2O) was added dropwise
7. additionAfter the addition
8. stirringstirring
9. waitwas continued at room temperature for a period of about 1 hour
10. customAfter this time the reaction mixture was transferred into a separatory funnel
11. extractionextracted with methylene chloride
12. extractionDuring extraction a solid precipitate
13. customformed
14. filtrationThe precipitate was recovered by filtration
15. extractionThe remaining aqueous phase was then extracted with ether
16. extractionthe ether extract
17. extractionextract
18. dry with materialThe extracts were then dried over anhydrous magnesium sulfate
19. filtrationfiltered
20. customleaving a solid residue
21. customobtained from a repeat of the foregoing procedure
22. customthe combined products were recrystallized from methanol
23. customThe resulting product was dried under vacuum at 80° C. for about 8 hours

ORD record

ord-ad48bd0dad444fea90316e4aa1837519

Source dataset

uspto-grants-1982_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04322414