Diisopropylamine → 5-Chloro-2-cyclopropyl-valeric acid

Temperature

-78 °C

n-Butyl lithium (2.64 M solution in hexane, 3.8 ml) was added dropwise to a solution of diisopropylamine (1.5 ml) in THF (15 ml) at −30° C., and the reaction solution was stirred at the same temperature for 15 minutes. The reaction solution was cooled to −78° C. Then, a solution of cyclopropylacetic acid (CAS No. 5239-82-7, 500 mg) in THF (3 ml) was added dropwise and the reaction solution was further stirred at room temperature for three hours. The reaction solution was cooled to 0° C., and then 1-bromo-3-chloropropane (CAS No. 109-70-6, 0.55 ml) was added dropwise. The reaction solution was stirred at the same temperature for 10 minutes and at room temperature for further one hour. Ice water and diethyl ether were added to the reaction solution, and the aqueous layer was separated. Then, 5 N hydrochloric acid (3 ml) and ethyl acetate were added to the aqueous layer, and the organic layer was separated. The resulting ethyl acetate layer was washed with brine, dried over anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain crude 5-chloro-2-cyclopropyl-valeric acid (550 mg).

1. stirringthe reaction solution was further stirred at room temperature for three hours
2. temperatureThe reaction solution was cooled to 0° C.
3. addition109-70-6, 0.55 ml) was added dropwise
4. stirringThe reaction solution was stirred at the same temperature for 10 minutes and at room temperature for further one hour
5. customthe aqueous layer was separated
6. additionThen, 5 N hydrochloric acid (3 ml) and ethyl acetate were added to the aqueous layer
7. customthe organic layer was separated
8. washThe resulting ethyl acetate layer was washed with brine
9. dry with materialdried over anhydrous magnesium sulfate
10. concentrationconcentrated under reduced pressure

ORD record

ord-ff0fa079d5834e6dac24e3cc6e5b6e12

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07935815B2