cas 7474-05-7, (R)-(+)-2-Chloropropionic acid

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Preparation method of D-2-chloropropionyl chloride and D-2-chloropropionyl chloride
The invention is applicable to the technical field of synthesis of medical intermediates, and provides a preparation method of D-2-chloropropionyl chloride and D-2-chloropropionyl chloride, the preparation method comprises the following steps: adding L-ethyl lactate and a catalyst into a reaction vessel, dropwisely adding thionyl chloride at -10-10 DEG C, heating to 65-70 DEG C, and carrying out heat preservation reaction; after the reaction is finished, cooling to 10-30 DEG C, and carrying out reduced pressure concentration and other treatment to obtain ethyl D-2-chloropropionate; adding resin, anhydrous formic acid and water, heating to 70-100 DEG C, and reacting for 2-5 hours; after the reaction is finished, cooling to 10-30 DEG C, filtering, and distilling to obtain D-2-chloropropionicacid; and dropwise adding thionyl chloride at 0-5 DEG C, heating to 45-65 DEG C, carrying out heat preservation reaction, and carrying out vacuum concentration and distillation treatment to obtain the product. The method realizes 10kg-grade large-scale production of D-2-chloropropionyl chloride, and has the advantages of high yield, high purity, recyclable catalyst, and no need of rectification equipment.
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Paragraph 0055; 0058-0059; 0065; 0068-0069; 0076; 0079-0080

(2021/03/13)

Preparation method of alpha-chloro carboxylic acid
The invention discloses a preparation method of alpha-chloro carboxylic acid. According to the preparation method, amino acids are dissolved into hydrochloric acid to form a homogeneous solution; thenobtained homogeneous solution and a sodium nitrite water solution are simultaneously pumped into a mixing valve through an injection pump A and an injection pump B of a micro-channel reaction apparatus; after the solutions are fully mixed, the mixed solution is pumped into a micro reactor of the micro-channel reaction apparatus to carry out reactions at a constant flowing speed, and the flow-outliquid namely alpha-chloro carboxylic acid is collected. The provided method realizes the continuous production of alpha-chloro carboxylic acid; furthermore, the product quality is good, the operationis simple, the using amount of raw materials is little, the process is safe, the method is green and environmentally friendly, energy is saved, the efficiency is high, and thus the method is suitablefor industrial production.
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Paragraph 0060; 0061

(2018/04/26)

Method for synthesizing (R)-2-chloropropionic acid by solid acid catalysis and trans-esterification reaction based on UIO-66
The invention provides a method for synthesizing (R)-2-chloropropionic acid by a solid acid catalysis and trans-esterification reaction based on UIO-66. The method comprises the following steps: (1) preparation of a solid acid catalyst SO4/UIO-66; and (2) preparation of (R)-2-chloropropionic acid. According to the method, UIO-66 is adopted as a solid acid catalyst of a substrate, the catalyst has strong acidity, so that the catalyst can effectively catalyze the trans-esterification reaction for synthesizing (R)-2-chloropropionic acid, the transformation rate is higher than 98%, side effects are less, and the catalyst can be used repeatedly, and therefore, the generation of tailings is effectively avoided, the production cost is lowered, and environmental protection is facilitated.
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Paragraph 0010; 0012; 0014

(2017/07/20)

Roof shape chiral alcohol: auxiliary for asymmetric synthesis of α-halo acid derivatives
Roof shape chiral enantiopure alcohol, obtained by bio-catalytic separation of isomers, was used as a new auxiliary for asymmetric synthesis of α-halo acid derivatives. Esterification reaction of roof shape chiral enantiopure alcohol and racemic α-halo acids in the presence of DCC, DMAP furnished diastereomers of ester in non-racemic manner. Diastereoselectivity up to 90% was observed, the absolute configuration of newly generated chiral center was established by the single crystal X-ray diffraction analysis.
Jain, Nilesh,Bedekar, Ashutosh V.
supporting information
p. 692 - 695
(2016/01/26)

COMPOUNDS FOR USE IN THE TREATMENT OF INFECTIOUS DISEASES
The present invention relates to compounds of formula (I), wherein R1, R2, R3, R4, R5 and R6 are as described herein, and their prodrugs or pharmaceutically acceptable salt, enantiomer or diastereomer thereof, and compositions including the compounds and methods of using the compounds.
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Page/Page column 59-60

(2016/05/02)

Ester exchange method for preparing high purity R-(+) - 2-chloropropionic acid process of
The invention discloses a process for preparing high-optical-purity R-(+)-2-chloropropionic acid through an ester exchange method. The process comprises the following steps: placing ethyl chloropropionate in a reactor, sequentially adding formic acid with the mass fraction of 94% and strong-acid cation exchange resin under stirring, slowly heating to 54DEG C, extracting ethyl formate, continuously heating, and recovering formic acid; and forming a negative pressure after the recovery of formic acid, and extracting R-(+)-2-chloropropionic acid. The process has the advantages of simple technology, no strong acidic tails, environmental protection and short production period, and the optical purity and the yield of the prepared R-(+)-2-chloropropionic acid are not smaller than 99% and not smaller than 90% respectively.
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Paragraph 0016; 0017; 0018

(2016/10/07)

THIOLACTONE ANTIBIOTICS
This invention provides a compound having the structure (I) wherein R1 is H, (II) or (III), wherein n and q are independently an integer from 0 to 8; A is absent or present and when present is (IV), (V), (VI), (VII), (VIII), or (IX), wherein m is an integer from 0 to 8; R3 is an amino, alkyl, aryl, heteroaryl, diol, piperazine, morpholine, piperidine, triazole, azide or biphenyl, each with or without substitution, branched or unbranched, or (X); and R4 is alkyl, aryl, or heteroaryl, each with or without substitution, branched or unbranched, R2 is H, CH3, or alkyl, aryl, heteroaryl, pyrrole, diazole, or triazole, each with or without substitution, branched or unbranched, or (XI), wherein n and q are independently an integer from 0 to 8; A is absent or present and when present is (IV), (V), (VI), (VII), or (VIII); and R6 is azide, methoxy, trifluoromethyl, biphenyl, substituted phenyl, substituted triazole, or alkyl, aryl or heteroaryl, with or without substitution, branched or unbranched, when R1 is H then R2 is other than H or CH3, and when R2 is H or CH3 then R1 is other than H, or a pharmaceutically acceptable salt thereof.
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Page/Page column 53

(2012/10/18)

Design and synthesis of chromogenic thiopeptolide substrates as MetAPs active site probes
Twenty one chromogenic thiopeptolide substrates were designed and synthesized as the active site probes and analyzed with each S1 site of mutant residues and enzymes of wild-type MetAP1s. The preliminary enzymatic experiments indicate that cysteine 70 or 202, at either Escherichia coli or human MetAP1, played a crucial role in the methionine hydrolysis.
Cui, Yong-Mei,Li, Jing-Ya,Chen, Ling-Ling,Li, Jia,Ye, Qi-Zhuang,Nan, Fa-Jun
p. 2853 - 2861
(2007/10/03)

Direct Organocatalytic Asymmetric α-Chlorination of Aldehydes
The direct organocatalytic enantioselective α-chlorination of aldehydes has been developed. The reaction proceeds for a series of different aldehydes with NCS as the chlorine source using easily available catalysts such as L-proline amide and (2R,5R)-diphenylpyrrolidine. The α-chloro aldehydes are obtained in up to 99% yield and up to 95% ee. The synthetic utility of the enantioselective α-chlorination of aldehydes is demonstrated by transformation of the α-chloro aldehydes to the corresponding α-chloro alcohols (>90% yield) by standard reduction and further transformation to both a terminal epoxide and amino alcohol, both obtained without loss of optical purity. Oxidation of the α-chloro aldehydes followed by esterification gave optically active α-chloro esters without loss of optical purity. It is demonstrated that these optically active α-chloro esters can be converted into nonproteinogenic amino acids in overall high yields, maintaining the enantiomeric excess obtained in the catalytic enantioselective α-chlorination step. Copyright
Halland, Nis,Braunton, Alan,Bachmann, Stephan,Marigo, Mauro,Jorgensen, Karl Anker
p. 4790 - 4791
(2007/10/03)

A flexible route to (5R)-thiolactomycin, a naturally occurring inhibitor of fatty acid synthesis.
[formula: see text] A new and efficient asymmetric synthesis of naturally occurring (5R)-thiolactomycin (1) using D-alanine as the source of chirality is described.
McFadden, Jill M,Frehywot, Gojeb L,Townsend, Craig A
p. 3859 - 3862
(2007/10/03)

Mapping the substrate selectivity of new hydrolases using colorimetric screening: Lipases from Bacillus thermocatenulatus and Ophiostoma piliferum, esterases from Pseudomonas fluorescens and Streptomyces diastatochromogenes
Recent advances in biochemistry and molecular biology have simplified the discovery and preparation of new hydrolases. Although these hydrolases might solve problems in organic synthesis, measuring their selectivity, especially enantioselectivity, remains tedious and time consuming. Recently, we developed a colorimetric screening method to measure the enantioselectivity of hydrolases. Here we apply this rapid screening method to map the substrate selectivity of four new hydrolases: lipases from the thermophilic Bacillus thermocatenulatus (DSM 730, BTL2) and a filamentous fungus Ophiostoma piliferum (NRRL 18917, OPL) and esterases from two bacteria, Pseudomonas fluorescens (SIK-W1, esterase I, PFE) and Streptomyces diastatochromogenes (Tue 20, SDE). We screened a general library of 29 substrates and a chiral library of 23 pairs of enantiomers. All four hydrolases catalysed the hydrolysis of unnatural substrates, but the two lipases accepted a broader range of substrates than the two esterases. As expected, the two lipases favoured more hydrophobic substrates, while the two esterases showed a preference for smaller substrates. Several moderately enantioselective reactions were identified for the solketal esters: BTL2, butyrate, E = 7.9 (R); octanoate, E = 4.9 (R) and 3-bromo-2-methyl propionate methyl esters, PFE, E = 12 (S); SDE, E = 5.6 (S). OPL showed low enantioselectivity toward all substrates tested. The current colorimetric screen could not measure the selectivity for several slow-reacting substrates. Traditional screening identified high enantioselectivity of BTL2 and PFE toward one of these slow substrates, 1-phenylethyl acetate (E>50).
Liu, Andrew Man Fai,Somers, Neil A.,Kazlauskas, Romas J.,Brush, Terry S.,Zocher, Frank,Enzelberger, Markus M.,Bornscheuer, Uwe T.,Horsman, Geoff P.,Mezzetti, Alessandra,Schmidt-Dannert, Claudia,Schmid, Rolf D.
p. 545 - 556
(2007/10/03)

(R)- and (S)-3-hydroxy-4,4-dimethyl-1-phenyl-2-pyrrolidinone as chiral auxiliaries in the enantioselective preparation of α-aryloxypropanoic acid herbicides and α-chlorocarboxylic acids
rac-α-Chlorocarboxylic acids, rac-9a-e, were formally deracemized by reaction of the corresponding acyl chlorides with the chiral auxiliaries (R)- and (S)-3-hydroxy-4,4-dimethyl-1-phenyl-2-pyrrolidinone, (R)- and (S)-4, followed by mild alkaline hydrolysis. The highest o.p. (99%) was obtained in the case of (S)-α-chloropropanoic acid, a known precursor for the synthesis of (R)-α-aryloxypropanoic acid herbicides such as dichlorprop-P, (R)-3a, or mecoprop-P, (R)-3b, which, together with their enantiomers, were also obtained in moderate e.e.s by dynamic kinetic resolution from (αRS,3S)-4,4- dimethyl-2-oxo-l-phenylpyrrolidin-3-yl α-bromopropanoate, (αRS,3S)-6, by reaction with the corresponding phenoxide followed by mild acid hydrolysis.
Camps, Pelayo,Perez, Francesc,Soldevilla, Nuria
p. 2065 - 2079
(2007/10/03)

Empirical rules for the enantiopreference of lipase from Aspergillus niger toward secondary alcohols and carboxylic acids, especially α-amino acids
Lipase from Aspergillus niger (ANL, Amano lipase AP) catalyzes enantioselective hydrolysis and acylation reactions. To aid in the design of new applications of this lipase, we propose two empirical rules that predict which enantiomer reacts faster. For secondary alcohols, a rule proposed previously for other lipases also works for ANL, but with lower reliability (77%, 37 of 48 examples). For carboxylic acids, we examined both crude and partially-purified ANL because commercial ANL contains contaminating hydrolases. Partial purification removed a contaminating amidase and increased the enantioselectivity of ANL toward many α-amino acids, including cyclic amino acids. Unlike other lipases, ANL readily accepts positively-charged substrates and shows the highest enantioselectivity towards α-amino acids. Although a rule based on the sizes of the substituents could not predict the fast-reacting enantiomer, a rule limited to α-amino acids did predict the fast-reacting enantiomer. We estimate that the charged α-amino group contributes a factor of 40-100 (ΔΔ≠ = 2.2-2.7 kcal/mol) to the enantioselectivity of ANL towards carboxylic acids.
Janes, Lana E.,Kazlauskas, Romas J.
p. 3719 - 3733
(2007/10/03)

Asymmetric Synthesis of 2-Chloro- and 2-Bromo-alkanoic acids by Halogenation of α-D-Glucofuranose-Derived Silyl Ketene Acetals.
Optically active (S)-2-bromo- and 2-chloro-alkanoic acids 6 and 7 have been obtained via the diastereoselective halogenation of chiral silyl ketene acetals 3a-f, and subsequent saponification of the resulting crude esters.Examples characterized by e.e. values up to 95percent are reported.The diastereoface selectivity is independent of the silyl ketene acetal E/Z configuration.
Angibaud, P.,Chaumette, J. L.,Desmurs, J. R.,Duhamel, L.,Ple, G.,et al.
p. 1919 - 1932
(2007/10/03)

Specific esterase activity of subtilisin toward esters of α-haloacids
Esters of α-haloacids are specific substrates for subtilisin which catalyses their hydrolysis in aqueous media. The same esters undergo transesterifications in organic solvents in the presence of subtilisin immobilized on an alumina-phosphate complex.
Pugniere,Juan, C. San,Previero
p. 4883 - 4886
(2007/10/02)

ENZYMATIC RECOGNITION OF DIASTEREOMERIC ESTERS
Aiming to improve the enantioselectivity of enzymatic resolution of esters, lipase catalyzed hydrolysis of (D)- and (L)-2-chloropropanoates of four racemic alcohols and transesterification of ethyl (DL)-2-chloropropanoate with optically pure alcohols was investigated.Thus, (rac)-endo-2-norbornyl (L)-2-chloropropanoate was hydrolized by lipase P about 5 times more selectively than its corresponding (D)-counterpart and optically pure (1R,2S,5R)-menthol was obtained by transesterification of its racemate with ethyl (D)-2-chloropropanoate using Candida cylindracea (CC)lipase.From the results obtained it seems obvious that lipases CC and P mainly can recognize the chirality of an alcohol moiety rather than that of an acid
Rabiller, C. G.,Koenigsberger, .,Faber, K.,Griengl, H.
p. 4231 - 4240
(2007/10/02)

Chiral Mesogenic Compounds: Carbocyclic and Heterocyclic Schiff Bases
Five different chiral p-substituted anilines derived from 4-aminobenzoic acid and from 4-aminophenol were condensed with four carbocyclic and heterocyclic aldehydes in order to obtain chiral Schiff bases resembling DOBAMBC and HOBACPC.With the exception of the pyridine-3-carboxaldehyde derivatives, the compounds are mesomorphic.Some of the compounds exhibit ferroelectric SC* phases, and all exhibit SA or Ch mesophases on heating.Benzaldehyde and pyridine-2-carboxaldehyde derivatives show similar mesomorphic behavior, as was to be expected from MNDO semiempirical calculations.Values of the spontaneous polarization of certain compounds were measured.
Barbera, J.,Melendez, E.,Serrano, J. L.,Sierra, M. T.,Ezcurra, A.,Jubindo, M. A. Perez
p. 151 - 158
(2007/10/02)