Tetrahydrofuran → 8-Chlorobenzofuro[3,2-b]pyridine

Temperature

-10 °C

The 500 mL round-bottom flask, equipped with magnetic stirrer and reflux condenser was charged with 2-(5-chloro-2-methoxyphenyl)pyridin-3-amine (9.00 g, 39 mmol), 70 mL THF, 70 mL HBF4 (50% in water) and 40 mL H2O. Reaction mixture was cooled to −10° C., and solution of sodium nitrite (5.6 g in 20 mL water) was added dropwise. Reaction mixture was warmed gradually to room temperature and stirred overnight. The reaction mixture was diluted with 500 mL of water and extracted with ethyl acetate (4×50 mL). Organic fractions were combined, dried over sodium sulfate and evaporated, the residue was subjected to column chromatography on silica gel with hexane/ethyl acetate 9/1 mixture, providing 8-chlorobenzofuro[3,2-b]pyridine (6.00 g, colorless needles from hexane/ethyl acetate).

1. customThe 500 mL round-bottom flask, equipped with magnetic stirrer
2. temperaturereflux condenser
3. customReaction mixture
4. customReaction mixture
5. temperaturewas warmed gradually to room temperature
6. extractionextracted with ethyl acetate (4×50 mL)
7. dry with materialdried over sodium sulfate
8. customevaporated

ORD record

ord-d5d42070d7de403183304f3f9672baca

Source dataset

uspto-grants-2012_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08221905B2