Hydrochloric Acid → 5-Fluoro-8-methoxychroman-6-carboaldehyde

Temperature

-74 °C

To a 130 ml THF solution containing 3.6 g of 5-fluoro-8-methoxychromane and 4.2 ml of N,N,N′,N′,N″-pentamethyldiethylenetriamine there was added dropwise 8 ml of n-butyllithium (2.55 M, hexane solution) at −74° C. After stirring at −74° C. for 1 hour, N-formylmorpholine was added. Stirring was continued for 1 hour at room temperature, and then 1N hydrochloric acid was added to the reaction mixture while cooling on ice, and the mixture was extracted with ethyl acetate and dried over anhydrous magnesium sulfate. The desiccant was filtered out and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate-heptane system) to obtain the target compound (1.50 g) as a colorless solid.

1. stirringStirring
2. waitwas continued for 1 hour at room temperature
3. temperaturewhile cooling on ice
4. extractionthe mixture was extracted with ethyl acetate
5. dry with materialdried over anhydrous magnesium sulfate
6. filtrationThe desiccant was filtered out
7. concentrationthe filtrate was concentrated under reduced pressure
8. customThe residue was purified by silica gel column chromatography (ethyl acetate-heptane system)

ORD record

ord-bdbeee518c844a99a36f2fb60e167fb4

Source dataset

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07807690B2