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