Dimethylformamide → 3-Fluoro-2-pyridinecarboxaldehyde

To a mixture of a 1.6M n-butyl lithium hexane solution (35 ml) and diethyl ether (200 ml) was added, at -78° C. under argon atmosphere, a solution of 1,4-diazabicyclo[2,2,21octane (6.35 g) in diethyl ether (200 ml), which was stirred for one hour at temperatures ranging from -70° to -50° C. To the mixture was added 3-fluoropyridine (5.00 g) at -70° C., and the mixture was stirred for one hour at temperatures ranging from -70° to -60° C. To the reaction mixture was added at -70° C. DMF (9.41 g). The mixture was stirred for one hour at temperatures ranging from -70° to -50° C., which was then poured into a saturated aqueous saline solution, followed by extraction with ethyl acetate/chloroform (about 4:1). The extract solution was washed with a saturated aqueous saline solution, dried (anhydrous sodium sulfate), and concentrated. The concentrate was purified by means of a silica gel column chromatography (eluent: ethyl acetate/hexane) to give 3-fluoro-2-formylpyridine (2.75 g, m.p. 52°-53° C.). Reference Example 47 (Production of Compound D-6)

1. additionwas added, at -78° C. under argon atmosphere
2. customranging from -70° to -50° C
3. customranging from -70° to -60° C
4. additionTo the reaction mixture was added at -70° C
5. stirringThe mixture was stirred for one hour at temperatures
6. customranging from -70° to -50° C.
7. additionwhich was then poured into a saturated aqueous saline solution
8. extractionfollowed by extraction with ethyl acetate/chloroform (about 4:1)
9. washThe extract solution was washed with a saturated aqueous saline solution
10. dry with materialdried (anhydrous sodium sulfate)
11. concentrationconcentrated
12. customThe concentrate was purified by means of a silica gel column chromatography (eluent: ethyl acetate/hexane)

ORD record

ord-43427f9afeaa4a10bfd24781954a3569

Source dataset

uspto-grants-1998_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05716971