Hydrochloric Acid → t-Butyl 3-(1-carboxycyclopentyl)propanoate

To a 50 ml round-bottomed flask under nitrogen was added lithium diisopropylamide (10.95 mL, 21.90 mmol). The solution was cooled to −20° using a controlled dry ice/acetonitrile bath. Cyclopentanecarboxylic acid (1.187 mL, 10.95 mmol) in dry THF (10 mL) was added over 5 minutes, keeping the temperature at −20° C. The mixture was warmed to room temperature, stirred for one hour, then cooled to −78° C. Tert-butyl acrylate (1.685 mL, 10.95 mmol) in dry THF (10 mL) was added dropwise over 5 min, keeping the temperature at −70° C. After 2 hours at −70° C., the mixture was quickly warmed to 0° C., acidified with 5N HCl, and extracted with hexane. The hexane extract was washed with water and saturated sodium bicarbonate, water, and dried over MgSO4, and then recrystallized from hexanes. Recovered 1-(3-tert-butoxy-3-oxopropyl)cyclopentanecarboxylic acid (1.8 g, 7.43 mmol, 67.8% yield).

1. temperatureThe solution was cooled to −20°
2. customat −20° C
3. temperaturecooled to −78° C
4. customat −70° C
5. waitAfter 2 hours at −70° C.
6. temperaturethe mixture was quickly warmed to 0° C.
7. extractionextracted with hexane
8. extractionThe hexane extract
9. washwas washed with water and saturated sodium bicarbonate, water
10. dry with materialdried over MgSO4
11. customrecrystallized from hexanes

ORD record

ord-55e7bf8da36c455ba71894a42fd13a0b

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09284283B2