81 results about "Succinonitrile" patented technology

The invention belongs to the technical field of lithium ion batteries and particularly relates to a formation method of a lithium ion battery. The formation method comprises the following steps of: vacuumizing a battery to be injected and performing first injection on the battery; performing opening formation on the battery subjected to the first injection, wherein a formation current ranges from 0.1C to 1.5C; and performing second injection and encapsulation on the battery subjected to the formation, wherein electrolyte for the second injection comprises high-temperature additives including at least one of trimethylene sulfite, ethylene sulfate, succinonitrile and adiponitrile. Compared with the prior art, the formation method disclosed by the invention avoids the electrolyte leakage caused by quick gas production during deformation with a large current by virtue of the way of twice injection, and avoids the influence on the components of an SEI (Solid Electrolyte Interface) membrane due to adding the electrolyte additives once, thereby improving the low temperature performance of a battery cell; and as the battery cell has high temperature performance by virtue of the additives injected after the formation, and the formation time is shortened greatly, the process efficiency is enhanced greatly, and the production cost is reduced.

The present invention provides an improved process for the preparation of a compound of formula (I), which comprises the steps of: formula (I), (a) reacting isovaleraldehyde of formula (II) and alkyl cyanoacetate of formula (III) optionally in presence of salts of weak acid and weak base or weak base in a suitable solvent to get 2-cyano-5-methyl-hex-2-enoic acid alkyl ester of formula (IV); (b) reacting 2-cyano-5-methyl-hex-2-enoic acid alkyl ester of formula (IV) with a suitable cyanide source in water or in an organic solvent or mixture thereof to get 2-isobutylsuccinonitrile of formula (V); (c) obtaining optionally 2-isobutylsuccinonitrile of formula (V) by reacting isovaleraldehyde of formula (II) and alkyl cyanoacetate of formula (III) in presence of suitable cyanide source in water or in an organic solvent or mixture thereof in single step; (d) converting 2-isobutylsuccinonitrile of formula pa (V) to racemic 3-cyano-5-methyl-hexanoic acid or salt thereof of formula (VI) with a genetically modified nitrilase enzyme (Nit pt 9N_56_2) in water or optionally with an organic co-solvent at appropriate pH and temperature; (e) converting racemic 3-cyano-5-methyl-hexanoic acid or salt thereof of formula (VI) to racemic alkyl 3-cyano-5-methyl-hexanoate of formula (VII) by treatment with alcohol (R3OH) and acidic catalyst or alkyl halide (R3X) in presence of a base in a suitable solvent or a mixture of solvents thereof; (f) obtaining (S)-alkyl 3-cyano-5-methyl-hexanoate of formula (VIII) and (R)-3-cyano-5-methyl-hexanoic acid or salt thereof of formula (X) by enzymatic enantioselective hydrolysis in water or organic solvent or a mixture thereof from racemic alkyl 3-cyano-5-methyl-hexanoate of formula (VII); (g) obtaining optionally the compound of formula (VII) by racemizing unwanted (R)-3-cyano-5-methyl-hexanoic acid or salt thereof of formula (X) or substantially enriched (R)-3-cyano-5-methyl-hexanoic acid salt thereof of formula (X) in presence of a base in organic solvent or a mixture thereof; (h) converting (S)-alkyl 3-cyano-5-methyl-hexanoate of formula (VIII) to pregabalin of formula (I) by hydrolyzing ester group with suitable alkali or alkaline earth metal base followed by hydrogenation optionally in one pot in a solvent selected from water or other organic solvents or a mixture thereof in presence of a suitable hydrogenation catalyst.

The invention discloses a preparation method of 1,4,5,8-octane tetranitrile. 1,4,5,8-octane tetranitrile is prepared by adopting acrylonitrile and butanedinitrile as raw materials. The preparation method also has the advantages of high yield, easily-available raw materials, simplicity in reaction control, high product purity, and the like. The prepared material can form a film on the positive electrode surface to prevent transition metal ions from catalyzing electrolyte decomposition under high voltage, thus improving the battery performances.