Iodine → 2-Cyclopenten-1-one, 2-pentyl-

In a 100 ml four-neck flask fitted with a thermometer, a reflux condenser and a stirrer were placed 2-(1-hydroxypentyl)cyclopentanone (20 g) synthesized in Reference Example 1, iodine (0.01 g) and xylene (10 ml), and water was removed under refluxing, followed by 2 hours of the reaction at 170° C. The reaction mixture was washed with water and the layers were separated from each other. Further, the resulting organic layer was washed with saturated brine and separated. The organic layer was evaporated on a rotary evaporator under reduced pressure to recover xylene, whereby a crude product (19.8 g) was obtained. The product was distilled using a Claisen distillation apparatus to obtain 17.4 g of 2-pentyl-2-cyclopentenone (boiling point: 105° C./933 Pa; GC purity: 98.2%).

1. customIn a 100 ml four-neck flask fitted with a thermometer, a reflux condenser and a stirrer
2. customwas removed
3. temperatureunder refluxing
4. customfollowed by 2 hours of the reaction at 170° C
5. washThe reaction mixture was washed with water
6. customthe layers were separated from each other
7. washFurther, the resulting organic layer was washed with saturated brine
8. customseparated
9. customThe organic layer was evaporated on a rotary evaporator under reduced pressure
10. customto recover xylene, whereby a crude product (19.8 g)
11. customwas obtained
12. distillationThe product was distilled
13. distillationa Claisen distillation apparatus

ORD record

ord-a13caae62f0c4d7d80075dc60bfcf2bb

Source dataset

uspto-grants-2004_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06833481B2