Isopropanol → 1-Isopropoxy-1-cyclopentene

Temperature

50 °C

To a mixture of 56.0 grams (0.50 mol) of cycloheptanone, 107.0 grams (0.56 mol) of triisopropyl orthoformate and 44 grams of isopropanol (0.73 mol) in a 500 ml three-neck round bottom flask was added 2.8 grams (0.020 mol) of sodium hydrogensulfate monohydrate. Upon catalyst addition, the reaction temperature rose to 45° C., and was heated and maintained at 50° C. for about 5 hours. The progress of the reaction was monitored by GC until the ketone concentration was below 2%. The isopropanol and isopropyl formate by-products were removed by distillation under reduced pressure while the temperature of the reaction mixture was increased to a maximum of 60° C. The reaction mixture was cooled to room temperature and the pH value adjusted to about 7˜8 by adding 0.4 of gram potassium iso-propoxide. The mixture was then heated under reduced pressure to remove unreacted cycloheptanone and 1-isopropoxy-1-cyclopentene was isolated as a clear liquid at a yield of 60.1%. The purity of the product exceeded 98%.

1. additionUpon catalyst addition
2. customrose to 45° C.
3. temperaturewas heated
4. customThe isopropanol and isopropyl formate by-products were removed by distillation under reduced pressure while the temperature of the reaction mixture
5. temperaturewas increased to a maximum of 60° C
6. temperatureThe reaction mixture was cooled to room temperature
7. additionby adding 0.4 of gram potassium iso-propoxide
8. temperatureThe mixture was then heated under reduced pressure
9. customto remove unreacted cycloheptanone

ORD record

ord-856b56f1e8e84a669727cbb1d07ea4d7

Source dataset

uspto-grants-2001_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06235944B1