Dimethylformamide → 4-Chloro-5-fluoropyridine-3-carbaldehyde

Temperature

-78 °C

4-Chloro-3-fluoropyridine (1 g) was dissolved in tetrahydrofuran (15 ml), and the solution was then cooled to −78° C. Lithium diisopropylamide (1.1 M solution in tetrahydrofuran and n-hexane, 7.6 ml) was added dropwise thereto, and the mixture was stirred at the same temperature as above for 5 hours. Then, N,N-dimethylformamide (1 ml) was added thereto, and the mixture was further stirred for 30 minutes while being heated to room temperature. Saturated saline was added to the reaction solution, followed by extraction with ethyl acetate. The extract was washed with water and saturated saline in this order and then dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure. The obtained residue was purified by silica gel chromatography (n-hexane-ethyl acetate) to obtain the title compound (521 mg).

1. stirringthe mixture was further stirred for 30 minutes
2. temperaturewhile being heated to room temperature
3. additionSaturated saline was added to the reaction solution
4. extractionfollowed by extraction with ethyl acetate
5. washThe extract was washed with water and saturated saline in this order
6. dry with materialdried over anhydrous sodium sulfate
7. distillationThe solvent was distilled off under reduced pressure
8. customThe obtained residue was purified by silica gel chromatography (n-hexane-ethyl acetate)

ORD record

ord-b04ae81d28414ccd935165ee28c34685

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09187489B2