Hydrochloric Acid → 5-fluoro-8-methoxy-4H-benzo[1,3]dioxine-6-carbaldehyde

Temperature

-74 °C

To a solution of the 1.086 g of 5-fluoro-8-methoxy-4H-benzo[1,3]dioxine and 1.28 ml of N,N,N′,N′,N″-pentamethyldiethylenetriamine in 10 ml of THF there was added dropwise 2.4 ml of n-butyllithium (2.55 M, hexane solution) at −74° C. The mixture was stirred at −74° C. for 1 hour, and then 0.7 ml of N-formyhnorpholine was added. After stirring at room temperature for 1 hour, 1N hydrochloric acid was added thereto while cooling on ice, and the mixture was extracted with ethyl acetate and dried over anhydrous magnesium sulfate. The desiccating agent was filtered off and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate-heptane) to give the title compound (153 mg) as an oil.

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

ORD record

ord-104f161d4ded42f9a056ae2cb1c26fa9

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07928228B2