4476-02-2Relevant articles and documents
Enantioselective Synthesis of α-Thiocarboxylic Acids by Nitrilase Biocatalysed Dynamic Kinetic Resolution of α-Thionitriles
Lauder, Kate,Anselmi, Silvia,Finnigan, James D.,Qi, Yuyin,Charnock, Simon J.,Castagnolo, Daniele
supporting information, p. 10422 - 10426 (2020/07/24)
The enantioselective synthesis of α-thiocarboxylic acids by biocatalytic dynamic kinetic resolution (DKR) of nitrile precursors exploiting nitrilase enzymes is described. A panel of 35 nitrilase biocatalysts were screened and enzymes Nit27 and Nit34 were found to catalyse the DKR of racemic α-thionitriles under mild conditions, affording the corresponding carboxylic acids with high conversions and good-to-excellent ee. The ammonia produced in situ during the biocatalytic transformation favours the racemization of the nitrile enantiomers and, in turn, the DKR without the need of any external additive base.
Synthesis method 2- hydroxyl carboxylic ester (by machine translation)
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Paragraph 0052; 0053, (2020/05/05)
The method, is simple 2 - energy consumption, energy consumption is low, the production :(1) of waste water can be greatly reduced, the yield of the target product is high 2 - and the production cost ;(2) is greatly reduced (1). 2 - The method comprises the following steps, preparing 2 - hydroxycarboxylate, with an acid ;(3) by a byproduct ammonium salt (2) in step, and filtering the excess acid, to remove the byproduct ammonium salt, to obtain 2 - hydroxyl carboxylic acid ester product, by esterification reaction in step (, and filtering to remove 2 - the excess, alcohol), from, the reaction, solution obtained by the reaction solution; of the catalyst under the, action of, a catalyst, to obtain the product of the compound. (by machine translation)
Production system of 2-aminobutanamide
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Paragraph 0069; 0093; 0094; 0107-0113, (2020/04/17)
The utility model provides a production system of 2-aminobutanamide, which comprises a first reactor, a second reactor, a third reactor, a fourth reactor, a fifth reactor and a sixth reactor, the second reactor is communicated with the first reactor and is used for reacting 2-hydroxybutyronitrile with an ammonia source to prepare 2-aminobutyronitrile; the third reactor is communicated with the second reactor and is used for carrying out hydrolysis reaction on the 2-aminobutyronitrile and strong base to prepare the 2-aminobutyramide. The device effectively reduces waste water, waste gas and waste residues, effectively reduces the use amount of hydrogen cyanide, improves the content of target products, and reduces the production cost.
Highly chemoselective and efficient Strecker reaction of aldehydes with TMSCN catalyzed by MgI2 etherate under solvent-free conditions
He, Kailun,Liu, Huijun,Zhang, Xingxian,Zhou, Jing
supporting information, p. 933 - 936 (2019/03/08)
Strecker reaction of various substituted aromatic aldehydes, heteroaromatic aldehydes, aliphatic aldehydes and α,β-unsaturated aldehydes with trimethylsilyl cyanide (TMSCN) was realized in the presence of 5 mol % of MgI2 etherate in a mild, efficient and highly chemoselective manner under solvent-free conditions.
Preparation method of (S)-(+)-2-aminobutanamide hydrochloride
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Paragraph 0032; 0033; 0034, (2019/01/23)
The invention discloses a synthetic process of a chiral drug (S)-alpha-ethyl-2-oxo-pyrrolidine acetamide (levetiracetam) intermediate (S)-(+)-2-aminobutanamide hydrochloride which has anti-epileptic function. The synthetic process comprises the following steps: performing condensation on acetone cyanohydrins and n-propanal as initial raw materials in the presence of a catalyst to obtain 2-hydroxybutyronitrile; then carrying out a reaction with ammonia to obtain 2-amino butyronitrile; then carrying out hydrolysis to obtain 2-aminobutanamide; then splitting and salifying the 2-aminobutanamide to obtain a target product. The synthetic process is high in yield, the raw materials are low in price and are easily purchased on a large scale, and the synthetic process overcomes the defects that several existing processes need highly toxic and highly polluting raw materials and is simple in process operation and low in cost. Mother liquor after splitting is further racemized and split and is recycled repeatedly, so that the synthetic process is suitable for industrial production.
Preparation method and preparation system of 2-aminobutyramide
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Paragraph 0091; 0092-0010, (2019/10/01)
The invention provides a preparation method and a preparation system of 2-aminobutyramide. The preparation method comprises: (1) generating 2-hydroxybutyronitrile from hydrogen cyanide and n-propanalunder the action of a first catalyst; (2) adding an ammonia source and a second catalyst to the 2-hydroxybutyronitrile obtained in the step (1), and carrying out a reaction to generate 2-aminobutyronitrile; and (3) removing the excess ammonia from the reaction solution obtained in the step (2), adding a strong base and a third catalyst, and carrying out a hydrolysis reaction to obtain DL-2-aminobutanamide. According to the present invention, with the method and the system, the wastewater, the waste gas and the waste residue can be effectively reduced, the consumption of hydrogen cyanide can beeffectively reduced, the content of the target product can be increased, and the production cost can be reduced.
Stereodivergence in the Ireland-Claisen Rearrangement of α-Alkoxy Esters
Podunavac, Ma?a,Lacharity, Jacob J.,Jones, Kerry E.,Zakarian, Armen
supporting information, p. 4867 - 4870 (2018/08/24)
A systematic investigation into the Ireland-Claisen rearrangement of α-alkoxy esters is reported. In all cases, the use of KN(SiMe3)2 in toluene gave rearrangement products corresponding to a Z-enolate intermediate with excellent diastereoselectivity, presumably because of chelation control. On the other hand, chelation-controlled enolate formation could be overcome for most substrates through the use of lithium diisopropylamide (LDA) in tetrahydrofuran (THF).
Fast microwave-assisted resolution of (±)-cyanohydrins promoted by lipase from Candida antarctica
Ribeiro, Sandra S.,Ferreira, Irlon M.,Lima, Jo?o P. F.,De Sousa, Bruno A.,Carmona, Rafaela C.,Santos, Alcindo A. Dos,Porto, André L. M.
, p. 1344 - 1350 (2015/07/15)
Enzymatic kinetic resolution (EKR) of (±)-cyanohydrins was performed by using immobilized lipase from Candida antarctica (CALB) under conventional ordinary conditions (orbital shaking) and under microwave radiation (MW). The use of microwave radiation contributed very expressively on the reduction of the reaction time from 24 to 2 h. Most importantly, high selectivity (up to 92percent eep) as well as conversion was achieved under MW radiation (50-56percent).
An efficient cyanosilylation of aldehydes with trimethylsilyl cyanide catalysed by MgI2 etherate
Wang, Yanping,Feng, Meiling,Liu, Yingshuai,Zhang, Xingxian
, p. 566 - 567,2 (2020/09/16)
A convenient procedure for the synthesis of cyanohydrins by the addition of trimethylsilyl cyanide to aromatic aldehydes, heteroaromatic aldehydes, aliphatic aldehydes and unsaturated aldehydes catalysed by MgI2 etherate (MgI2(OEt2)n) in good to excellent yields is described.
Chiral solvating agents for cyanohydrins and carboxylic acids
Moon, Lomary S.,Pal, Mohan,Kasetti, Yoganjaneyulu,Bharatam, Prasad V.,Jolly, Ravinder S.
body text, p. 5487 - 5498 (2010/11/05)
We have shown that a structure as simple as an ion pair of (R)- or (S)-mandelate and dimethylamminopyridinium ions possesses structural features that are sufficient for NMR enantiodiscrimination of cyanohydrins. Moreover, 1H NMR data of cyanohydrins of known configuration obtained in the presence of the mandelate-dimethylaminopyridinium ion pair point to the existence of a correlation between chemical shifts and absolute configuration of cyanohydrins. Mandelate-DMAPH+ ion pair and mandelonitrile form a 1:1 complex with an association constant of 338 M-1 (ΔG 0, -3.4 kcal/mol) for the (R)-mandelonitrile/(R)-mandelate-DMAPH + and 139 M-1 (ΔG0, -2.9 kcal/mol) for the (R)-mandelonitrile/(S)-mandelate-DMAPH+ complex. To understand the origin of enantiodiscrimination, the geometry optimization and energy minimization of the models of ternary complexes of (S)-mandelonitrile/(R)- mandelate/DMAPH+ and (S)-mandelonitrile/(S)-mandelate/DMAPH + complexes was performed using DFT methodology (B3LYP) with the 6-31+G(d) basis set in Gaussian 3.0. Further, analysis of optimized molecular model obtained from theoretical studies suggested that (i) DMAP may be replaced with other amines, (ii) the hydroxyl group of mandelic acid is not necessary for stabilization of ternary complex and may be replaced with other groups such as methyl, (iii) the ion pair should form a stable ternary complex with any hydrogen-bond donor, provided its OH bond is sufficiently polarized, and (iv) α-H of racemic mandelic acid should also get resolved with optically pure mandelonitrile. These inferences were experimentally verified, which not only validated the proposed model but also led to development of a new chiral solvating agent for determination of ee of carboxylic acids and absolute configuration of aryl but not alkyl carboxylic acids.
