Hydrochloric Acid → 2,3-Dihydrobenzofuran-5-carboxaldehyde

Temperature

-78 °C

To a solution of 5-bromo-2,3-dihydro-benzofuran described in Preparation Example 173 (15.0 g, 75.4 mmol) in tetrahydrofuran (300 mL) was added n-butyl lithium (31.2 mL, 82.9 mmol) at −78° C. The reaction solution was stirred for 85 minutes at −78° C., then, N,N-dimethytformamide (6.42 mL, 82.9 mmol) was added thereto, followed by stirring at room temperature for 1 hour. 1N Hydrochloric acid was added to the reaction solution, which was then extracted with ethyl acetate, and the organic layer was washed with brine. Anhydrous magnesium sulfate was added to the organic layer for drying, which was then filtered, the filtrate was concentrated in vacuo, the residue was purified by silica gel column chromatography (hexane/ethyl acetate=5/1), and the title compound (10.1 g, 90%) was obtained as a pale yellow oil.

1. additionN,N-dimethytformamide (6.42 mL, 82.9 mmol) was added
2. stirringby stirring at room temperature for 1 hour
3. extractionwas then extracted with ethyl acetate
4. washthe organic layer was washed with brine
5. additionAnhydrous magnesium sulfate was added to the organic layer
6. customfor drying
7. filtrationwhich was then filtered
8. concentrationthe filtrate was concentrated in vacuo
9. customthe residue was purified by silica gel column chromatography (hexane/ethyl acetate=5/1)

ORD record

ord-a8126f65267f442da71a08e88bb0c91a

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07932272B2