Preparation of 2,6-difluoropyridine-3-carbaldehyde_Industrial additives

Preparation background and overview of 2,6-difluoropyridine-3-carbaldehyde

2,6-Difluoropyridine-3-carboxaldehyde can be used as a pharmaceutical synthesis intermediate and can be prepared by formylation from 2,6-difluoropyridine as the reaction raw material. There are reports in the literature that it can be used as a battery electrolyte additive.

Preparation of 2,6-difluoropyridine-3-carbaldehyde

To a solution of 2,6-difluoropyridine (4.95 g, 43.0 mmol) in anhydrous THF (100 mL) cooled at -78 °C under nitrogen was added LDA (2.0 M in heptane/THF/ Ethylbenzene solution, 23.0 mL, 46.0 mmol). After the mixture was stirred at -78 °C for 30 minutes, 1-formylpiperidine (4.98 g, 44.0 mmol) was added. The mixture was stirred at -78 °C for 20 min, and aqueous HCl (3N, 60 mL) and Et₂O (50 mL) were added at -78 °C. Collect the ether layer, and extract the aqueous layer with Et₂O (3×100mL). The combined extracts were dried over anhydrous Na₂SO₄. After filtration, the solvent was removed and the residue was purified by silica gel flash chromatography (CH₂Cl₂/hexane, 1:1 v/v) to obtain a light yellow liquid. 2,6-difluoro-pyridine-3-carbaldehyde (1.41 g, 60%).

Preparation and application of 2,6-difluoropyridine-3-carbaldehyde

CN202010043273.X provides a high-voltage lithium-ion battery electrolyte that can form a tight and stable interface film at the positive and negative electrode interfaces under high voltage, inhibit electrolyte decomposition and transition metal ion dissolution, and improve battery cycle performance. additive. High-voltage lithium-ion battery electrolyte additives are compounds with pyridyl groups. The pyridyl compound is selected from 4-cyanopyridine, 3-cyanopyridine, 2-cyanopyridine, 2-cyano-5-nitropyridine, 2,4,6-sodium perborate tetrahydrate trimethyl Pyridine, 4-methylpyridine, 2-pyridinecarboxaldehyde, 4-acetylpyridine, 2-acetylpyridine, 5-methoxy-3-pyridinecarboxaldehyde, ethyl 3-fluoropyridine-2-carboxylate, 2-methoxy Base-3-trifluoromethylpyridine, 2-fluoro-4-bromopyridine, α-methylpyridine, 3,5-dinitropyridine-4-carbonitrile, 3-fluoro-2-pyridinecarbonitrile, 2 ,3-difluoro-5-chloropyridine, 3-fluoro-4-acetylpyridine, 2-acetyl-3-methylpyridine, 2,5-difluoropyridine, 2-chloro-3-fluoro-5- Bromopyridine, 2-fluoro-5-bromopyridine, 1,2-dipyridyl acetylene, 2,6-dibromopyridine, 3,5-dibromopyridine, 4-methoxypyridine, 3,5-dimethyl Pyridine, cesium bicarbonate 3,4-dichloropyridine, 4-pyridineacetonitrile, 2,3-dibromopyridine, 2,6-difluoropyridine, 2,6-difluoropyridine-3-carbaldehyde, etc.

References

[1] From PCT Int. Appl., 2007022371, 22 Feb 2007

[2][Invented in China] CN202010043273.X High-voltage lithium-ion battery electrolyte additive, electrolyte, battery and formation method thereof