Hydrochloric Acid → 94283-73-5

Temperature

40 °C

Commercially available 3,4-dihydroxybenzaldehyde (5 g, 36.2 mmol) and potassium carbonate (5.15 g, 37.3 mmol) were dissolved in N,N-dimethylformamide (20 mL), then 2-bromopropane (3.5 mL, 37.3 mmol) was added under nitrogen atmosphere at room temperature, and the mixture was heated and stirred at 40° C. for 2.5 hours. The reaction mixture was cooled to 0° C., and then 2 M hydrochloric acid, ethyl acetate, and water were added for partition. The aqueous layer was extracted with ethyl acetate, the combined organic layer was washed with water and a saturated saline solution, and the resultant was dried over anhydrous magnesium sulfate and then filtered. The solvent was evaporated, dichloromethane was added to the residue, the precipitate was separated by filtration, and the filtrate was concentrated under vacuum. The residue was purified with silica gel column chromatography (n-heptane:ethyl acetate=19:1-13:7) and then the target fraction was concentrated under vacuum to obtain the title compound (1.84 g, 28%).

1. temperaturethe mixture was heated
2. temperatureThe reaction mixture was cooled to 0° C.
3. customfor partition
4. extractionThe aqueous layer was extracted with ethyl acetate
5. washthe combined organic layer was washed with water
6. dry with materiala saturated saline solution, and the resultant was dried over anhydrous magnesium sulfate
7. filtrationfiltered
8. customThe solvent was evaporated
9. additiondichloromethane was added to the residue
10. customthe precipitate was separated by filtration
11. concentrationthe filtrate was concentrated under vacuum
12. customThe residue was purified with silica gel column chromatography (n-heptane:ethyl acetate=19:1-13:7)
13. concentrationthe target fraction was concentrated under vacuum

ORD record

ord-24cefadf88a84348b7706749bfc23f3c

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08933099B2