Water → 6-Bromo-3-pyridinecarboxaldehyde

Temperature

-78 °C

According to a procedure described in literature (Xin Wang et al., Tetrahedron. Lett., 2000, vol. 41, p. 4335], a solution of 2,5-dibromopyridine (3.17 g) in anhydrous diethyl ether (140 ml) was added dropwise with a 1.6 M solution of n-butyl lithium in hexane (11 ml) with cooling at −78° C. under argon gas atmosphere over 5 minutes, and stirred for 20 minutes. This reaction mixture was added dropwise with dehydrated DMF (1 ml) over 3 minutes, stirred for 30 minutes, then warmed to room temperature, and further stirred for 1 hour. The reaction mixture was added with water (20 ml), and extracted with ethyl acetate (30 ml×2). The organic layer was washed with saturated brine, and dried, and then the solvent was evaporated under reduced pressure. The residue was purified by column chromatography (Quad, hexane:ethyl acetate=6:1) to obtain the title compound (Intermediate Int. n-44, 1.46 g).

1. stirringstirred for 30 minutes
2. temperaturewarmed to room temperature
3. stirringfurther stirred for 1 hour
4. extractionextracted with ethyl acetate (30 ml×2)
5. washThe organic layer was washed with saturated brine
6. customdried
7. customthe solvent was evaporated under reduced pressure
8. customThe residue was purified by column chromatography (Quad, hexane:ethyl acetate=6:1)

ORD record

ord-5a088a7b14884a73a7f1c4a1b2e906b6

Source dataset

uspto-grants-2008_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07470807B2