10488-69-4

Basic information

• Product Name: ETHYLL-4-CHLORO-3-HYDROXY BUTYRATE
• Synonyms: ETHYLL-4-CHLORO-3-HYDROXY BUTYRATE;Ethyl-4-Chloro-4-HydroxyButyrate;COBE;DL-Ethyl 4-Chloro-3-hydroxybutyrate
• CAS NO: 10488-69-4
• Molecular Formula: C₆H₁₁ClO₃
• Molecular Weight: 166.60274
• EINECS: 1308068-626-2
• Mol File: 10488-69-4.mol
• Article Data: 173

Chemical Properties

• Melting Point: 136 °C
• Boiling Point: 263.44 °C at 760 mmHg
• Flash Point: 113.125 °C
• Appearance: /
• Density: 1.187 g/cm³
• Vapor Pressure: 0.00145mmHg at 25°C
• Refractive Index: 1.453
• PKA: 13.23±0.20(Predicted)
• CAS DataBase Reference: ETHYLL-4-CHLORO-3-HYDROXY BUTYRATE(CAS DataBase Reference)
• NIST Chemistry Reference: ETHYLL-4-CHLORO-3-HYDROXY BUTYRATE(10488-69-4)
• EPA Substance Registry System: ETHYLL-4-CHLORO-3-HYDROXY BUTYRATE(10488-69-4)

Safety Data

• Hazard Codes: Xi:Irritant
• Statements: R41:
• Safety Statements: S26:; S39:
• Hazardous Substances Data: 10488-69-4(Hazardous Substances Data)

Usage

Chemical Properties

Colorless or Light yellow liquid

InChI:InChI=1/C6H11ClO3/c1-2-10-6(9)3-5(8)4-7/h5,8H,2-4H2,1H3/t5-/m0/s1

Upstream product

• 64-17-5 ethanol 
• 201230-82-2 carbon monoxide 
• 106-89-8 epichlorohydrin 
• 539-88-8 4-oxopentanoic acid ethyl ester 
• 6737-16-2 4-chloromethyl-β-lactone 
• 51594-55-9 (R)-(-)-epichlorohydrin 
• 86728-85-0 ethyl 4-chloro-3-hydroxybutanoate 
• 618-36-0 rac-methylbenzylamine 
• 123-82-0 2-heptylamine 
• 22095-34-7 1-(furan-2-yl)ethanamine 
• 16493-63-3 (R)-(-)-3-hydroxy-4,4,4-trichlorobutyric β-lactone 
• 166896-25-9 ethyl (3R)-4,4,4-trichloro-3-hydroxybutanoate 
• 7152-15-0 ethyl 4-methyl-3-oxo-pentanoate 
• 90556-40-4 3-acetoxy-4-chlorobutyric acid ethyl ester 

Downstream Products

• 22677-21-0 4-hydroxy-2-oxopyrrolidine 
• 10488-69-4 ethyl (L)-4-chloro-3-hydroxybutyrate 
• 58081-05-3 (R)-3-hydroxybutyrolactone 
• 5469-16-9 (3S)-hydroxy-γ-butyrolactone 
• 10488-69-4 ethyl (S)-4-chloro-3-hydroxybutanoate 
• 497-23-4 2-buten-4-olide 
• 106941-19-9 (S)-4-chloro-3-hydroxybutyric acid 
• 139013-68-6 (3S)-4-chloro-1,3-butanediol 
• 125605-10-9 (3R)-4-chloro-1,3-butanediol 
• 27948-38-5 (1S)-1-(furan-2-yl)ethanamine 
• 222311-41-3 (3S,1'R)-4-chloro-N-<1-(2-furyl)ethyl>3-hydroxybutanamide 
• 123-82-0 (S)-2-heptylamine 
• 222311-43-5 (3S,1'R)-4-chloro-N-(2-heptyl)-3-hydroxybutanamide 
• 2627-86-3 (S)-1-phenyl-ethylamine 

Relevant articles and documents

Efficient synthesis of a chiral precursor for angiotensin-converting enzyme (ace) inhibitors in high space-time yield by a new reductase without external cofactors

A new reductase, CgKR2, with the ability to reduce ethyl 2-oxo-4-phenylbutyrate (OPBE) to ethyl (R)-2-hydroxy-4-phenylbutyrate ((R)-HPBE), an important chiral precursor for angiotensin-converting enzyme (ACE) inhibitors, was discovered. For the first time, (R)-HPBE with >99% ee was produced via bioreduction of OPBE at 1 M without external addition of cofactors. The space-time yield (700 g·L-1·d -1) was 27 times higher than the highest record.

Stereoselective reduction of α- and β-keto esters with aerobic thermophiles, Bacillus strains

The first example of stereoselective reduction with aerobic thermophiles is reported. Various α- and β-keto esters were reduced stereoselectively to the corresponding alcohols by the aerobic thermophiles, Bacillus strains. In particular, the reduction of ethyl 3-methyl-2-oxobutanoate with B. stearothermophilus DSM 297 gave the corresponding (R)-alcohol with high yield in excellent enantioselectively (> 99% e.e.). The conversions of keto esters to the corresponding hydroxy esters with Bacillus strains were increased by introduction of glycerol in the reaction mixture as an additive.

Preparation of structurally diverse chiral alcohols by engineering ketoreductase CgKR1

Ketoreductases are tools for the synthesis of chiral alcohols in industry. However, the low activity of natural enzymes often restricts their use in industrial applications. On the basis of computational analysis and previous reports, two residues (F92 and F94) probably affecting the activity of ketoreductase CgKR1 were identified. By tuning these two residues, the CgKR1-F92C/F94W variant was obtained that exhibited higher activity toward all 28 structurally diverse substrates examined than the wild-type enzyme. Among them, 13 substrates have a specific activity over 50 U mg-1 (54-775 U mg-1). Using CgKR1-F92C/F94W as a catalyst, five substrates at high loading (>100 g-1 L-1) were reduced completely in gramscale preparative reactions. This approach provides accesses to pharmaceutically relevant chiral alcohols with high enantioselectivity (up to 99.0% ee) and high space-time yield (up to 583 g-1 L-1 day-1). Molecular dynamics simulations highlighted the crucial role of residues 92 and 94 in activity improvement. Our findings provide useful guidance for engineering other ketoreductases, especially those possessing a similar active pocket to that in CgKR1.

Efficient synthesis of an ε-hydroxy ester in a space-time yield of 1580 g L-1 d-1 by a newly identified reductase RhCR

A new NADH-dependent carbonyl reductase RhCR capable of efficiently reducing the ε-ketoester ethyl 8-chloro-6-oxooctanoate (ECOO) to give ethyl (S)-8-chloro-6-hydroxyoctanoate [(S)-ECHO], an important chiral precursor for the synthesis of (R)-α-lipoic acid, was identified from Rhodococcus sp. ECU1014. Using recombinant Escherichia coli cells expressing RhCR and glucose dehydrogenase used for the regeneration of cofactor, 440 g L-1 (2 M) of ECOO were stoichiometrically converted to (S)-ECHO in a space-time yield of 1580 g L-1 d-1 without the external addition of any expensive cofactor.

Baker's yeast: Improving the D-stereoselectivity in reduction of 3-oxo esters

The stereoselectivity of baker's yeast in the reduction of ethyl 3- oxopentanoate was shifted towards the corresponding (R)-hydroxy ester by sugar, heat treatment and allyl alcohol. The highest enantiomeric excesses obtained with baker's yeast with a good reduction capacity, 92-97%, were achieved by combining allyl alcohol and sugar; heat treatment did not increase the stereoselectivity further. With the use of this technique, ethyl (R)-3-hydroxyhexanoate, >99% ee, and ethyl (S)-4-chloro-3-hydroxybutanoate, 82-90% ee, were produced from the corresponding esters, and for the first time an excess of the (R)-enantiomer of ethyl 3-hydroxybutanoate was obtained with ordinary baker's yeast.

Stereoselective reduction of alkyl 3-oxobutanoate by carbonyl reductase from Candida magnoliae

The enantioselective reduction of alkyl 3-oxobutanoates by carbonyl reductase (S1) from Candida magnoliae was investigated. S1 reduced alkyl 4-halo-3-oxobutanoates to the corresponding enantiomerically pure (S)-3-hydroxy esters. Escherichia coli HB101 transformant co-overproducing the S1 and glucose dehydrogenase from Bacillus megaterium, produced optically pure alkyl 4-substituted-3-hydroxybutanoates in a two-phase water/organic solvent system.

A novel method to synthesize (L)-β-hydroxyl esters by the reduction with bakers' yeast

β-Keto esters are reduced stereoselectively into the corresponding (L)-β-hydroxyl esters in the presence of ethyl chloroacetate.

Practical application of recombinant whole-cell biocatalysts for the manufacturing of pharmaceutical intermediates such as chiral alcohols

We have developed efficient biocatalytic processes for the preparation of chiral alcohols, such as (R)-1,3-butanediol, ethyl (S)-4-chloro-3-hyroxybutanoate, ethyl (R)-4-chloro-3-hyroxybutanoate, (S)-5-chloro-2-pentanol, (R)-5-chloro-2-pentanol, and (S)-cyclopropylethanol by stereospecific enzymatic oxidoreduction on a practical level. These chiral alcohols are very important synthons for the synthesis of various pharmaceutical intermediates that lead to antibiotics and inhibitors of HMG-CoA reductase. Here, we present practical applications on biocatalysis using novel recombinant whole-cell biocatalysts that catalyzed enantioselective oxidation and asymmetric reduction with a coenzyme regeneration system.

Synthesis of both enantiomers of ethyl-4-chloro-3-hydroxbutanoate from a prochiral ketone using Candida parapsilosis ATCC 7330

Candida parapsilosis ATCC 7330 when grown in a medium containing glycerol reduced ethyl-4-chloro-3-oxobutanoate to (R)-ethyl-4-chloro-3-hydroxybutanote (ee >99%, yield: 94%) while glucose and sucrose grown cells yielded (S)-ethyl-4-chloro-3-hydroxybutanote (ee >99%, yield: 96%). The activity of ethyl-4-chloro-3-oxobutanoate reductase was higher in glucose-grown cells (160 U/g protein) when compared to sucrose (158 U/g protein) and glycerol (22 U/g protein). Both the enantiomers of ethyl-4-chloro-3-hydroxybutanoate (ee >99%) can thus be obtained using Candida parapsilosis ATCC 7330 by altering the carbon source in the growth medium.

A PRACTICAL ASYMMETRIC SYNTHESIS OF CARNITINE

The first efficient chemical synthesis of (R)-carnitine has been accomplished on the basis of homogenous enantioselective hydrogenation of ethyl 4-chloro-3-oxobutanoate.

Asymmetric synthesis of the chiral synthon ethyl (S)-4-chloro-3- hydroxybutanoate using Lactobacillus kefir

Lactobacillus kefir was used as the whole cell biocatalyst for the asymmetric reduction of ethyl 4-chloro acetoacetate 1 to the chiral synthon ethyl (S)-4-chloro-3-hydroxybutanoate 2. Ketoester 1 was obtained as micro-droplets, without the use of an organic solvent as substrate reservoir. 2 (1.2 M) was produced using 2-propanol as co-substrate with a final yield of 97% within 14 h. A high space-time yield and a high specific product capacity of 85.7 mmol/L h and of 24 mmol/gDCW were measured. The enantiomeric excess of the (S)-alcohol 2 was 99.5%.

Synthesis of a new class of chiral 1,5-diphosphanylferrocene ligands and their use in enantioselective hydrogenation

A new family of ferrocenylphosphane ligands has been prepared. Their flexible synthesis allows many structural modifications. The asymmetric induction of these ligands was examined in the hydrogenation of functionalized C=C, C=O, and C=N bonds. The enantioselectivity of the reaction was strongly dependent on the substituent R at the position α to the ferrocene moiety. In many cases, both enantiomeric β-hydroxyesters of the reduction product can be obtained by simply replacing a dimethylamino group in the ligand with a methyl group.

A novel reductase from Candida albicans for the production of ethyl (S)-4-chloro-3-hydroxybutanoate

A novel NADPH-dependent reductase (CaCR) from Candida albicans was cloned for the first time. It catalyzed asymmetric reduction to produce ethyl (S)-4-chloro-3-hydroxybutanoate ((S)-CHBE). It contained an open reading frame of 843 bp encoding 281 amino acids. When co-expressed with a glucose dehydrogenase in Escherichia coli, recombinant CaCR exhibited an activity of 5.7 U/mg with ethyl 4-chloro-3-oxobutanoate (COBE) as substrate. In the biocatalysis of COBE to (S)-CHBE, 1320mM (S)-CHBE was obtained without extra NADP+/NADPH in a water/butyl acetate system, and the optical purity of the (S)-isomer was higher than 99% enantiomeric excess.

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Altering the substrate specificity of reductase CgKR1 from Candida glabrata by protein engineering for bioreduction of aromatic α-keto esters

A versatile keto ester reductase CgKR1, exhibiting a broad substrate spectrum, was obtained from Candida glabrata by genome data mining. It showed the highest activity toward an aliphatic β-keto ester, ethyl 4-chloro-3-oxobutanoate (COBE), but much lower activity toward bulkier α-keto esters with an aromatic group, such as methyl ortho- chlorobenzoylformate (CBFM) and ethyl 2-oxo-4-phenylbutyrate (OPBE). By rational design of the active pocket, the substrate specificity of the reductase was significantly altered and this tailor-made reductase showed a much higher activity toward aromatic α-keto esters (～7-fold increase in k cat/Km toward CBFM) and lower activity toward aliphatic keto esters (～12-fold decrease in kcat/Km toward COBE). Meanwhile, the thermostability of the reductase was enhanced by a consensus approach. Such improvements may yield practical catalysts for the asymmetric bioreduction of these aromatic α-keto esters

Purification and Characterization of NADPH-Dependent Carbonyl Reductase, Involved in Stereoselective Reduction of Ethyl 4-Chloro-3-oxobutanoate, from Candida magnoliae

A NADPH-dependent carbonyl reductase was purified to homogeneity from Candida magnoliae AKU4643 through four steps, including Blue Sepharose affinity chromatography. The enzyme catalyzed the stereoselective reduction of ethyl 4-chloro-3-oxobutanoate to the corresponding (S)-alcohol with a 100% enantiomeric excess, which is a useful chiral building block for the chemical synthesis of pharmaceuticals. The relative molecular mass of the enzyme was estimated to be 76,000 on high performance gel filtration chromatography and 32,000 on SDS polyacrylamide gel electrophoresis. The enzyme reduced α, β-keto esters and conjugated diketones in addition to ethyl 4-chloro-3-oxobutanoate. The enzyme activity was inhibited by quercetin and HgCl2, but not by EDTA. The N-terminal amino acid sequence of the enzyme showed no apparent similarity with those of other oxidoreductases.

Asymmetric reduction of substituted α- and β-ketoesters by Bacillus pumilus Phe-C3

The enantioselective reduction of substituted α- and β-ketoesters using resting cells of Bacillus pumilus Phe-C3 was investigated. Effects of substrate concentration on the catalytic efficiency of the microorganism were studied. Preparative scale productions were carried out under the optimized conditions with 62.4-91.0% yields and 90.2-97.1% ee. The cells retained 80% of initial activity after recycling for six times.

Enantioselective hydrogenation of α- and β-functionalized ketones by Ru(II){AMPP} catalysts

Neutral ruthenium complexes bearing aminophosphine-phosphinite ligands have been applied in the enantioselective hydrogenation of α- (5-7) and β- (8-10) functionalized ketones. The corresponding hydroxycompounds are produced with enantiomeric excesses up to 63 and 85% respectively for the two types of substrates.

Asymmetric whole cell biotransformations in biphasic ionic liquid/water-systems by use of recombinant Escherichia coli with intracellular cofactor regeneration

Ionic liquids such as [BMIM][PF6] and [BMIM][NTF] are already known as good alternatives to organic solvents in biphasic biotransformation. Herein, we report about a systematic procedure based on physical properties to identify more commercially available ionic liquids exhibiting the potential to improve the efficiency of whole cell biocatalyses. This approach resulted in the identification of seven other water immiscible ionic liquids. These ionic liquids were rated by their biocompatibility, their substrate- and product-specific distribution coefficients and by for example performed asymmetric reductions of several prochiral ketones. With the use of a recombinant Escherichia coli as biocatalyst, overproducing a Lactobacillus brevis alcohol dehydrogenase and a Mycobacterium vaccae N10 formate dehydrogenase for cofactor regeneration, the great potential of asymmetric whole cell biotransformations in biphasic ionic liquid/water-systems were demonstrated in simple batch processes.

Identification of a Robust Carbonyl Reductase for Diastereoselectively Building syn-3,5-Dihydroxy Hexanoate: A Bulky Side Chain of Atorvastatin

t-Butyl-6-cyano-(3R,5R)-dihydroxyhexanoate is an advanced chiral precursor for the synthesis of the side chain pharmacophore of cholesterol-lowering drug atorvastatin. Herein, a robust carbonyl reductase (LbCR) was newly identified from Lactobacillus brevis, which displays high activity and excellent diastereoselectivity toward bulky t-butyl 6-cyano-(5R)-hydroxy-3-oxo-hexanoate (7). The engineered Escherichia coli cells harboring LbCR and glucose dehydrogenase (for cofactor regeneration) were employed as biocatalysts for the asymmetric reduction of substrate 7. As a result, as much as 300 g L-1 of water-insoluble substrate was completely converted to the corresponding chiral diol with >99.5% de in a space-time yield of 351 g L-1 d-1, indicating a great potential of LbCR for practical synthesis of the very bulky and bi-chiral 3,5-dihydroxy carboxylate side chain of best-selling statin drugs.

New method for the preparation of (R)-carnitine

A new method for the preparation of (R)-carnitine (1) has been developed from enantiomerically pure (R)-4-(trichloromethyl)-oxetan-2-one [(R)-2] which was easily obtained from the [2 + 2]-cycloaddition of ketene and chloral in the presence of catalytic amounts of poly(acryloyl quinidine). The key intermediate, ethyl (R)-3-hydroxy-4-chlorobutyrate [(R)-5], was prepared by ethanolysis of (R)-2 followed by selective bis-dechlorination of ethyl (R)-3-hydroxy-4,4,4-trichlorobutyrate [(R)-3].

Stereochemical Control of Yeast Reductions. 1. Asymmetric Synthesis of L-Carnitine

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Gene cloning and expression of Leifsonia alcohol dehydrogenase (LSADH) involved in asymmetric hydrogen-transfer bioreduction to produce (R)-form chiral alcohols

The gene encoding Leifsonia alcohol dehydrogenase (LSADH), a useful biocatalyst for producing (R)-chiral alcohols, was cloned from the genomic DNA of Leifsonia sp. S749. The gene contained an opening reading frame consisting of 756 nucleotides corresponding to 251 amino acid residues. The subunit molecular weight was calculated to be 24,999, which was consistent with that determined by polyacrylamide gel electrophoresis. The enzyme was expressed in recombinant Escherichia coli cells and purified to homogeneity by three column chromatographies. The predicted amino acid sequence displayed 30-50% homology to known short chain alcohol dehydrogenase/reductases (SDRs); moreover, the NADH-binding site and the three catalytic residues in SDRs were conserved. The recombinant E. coli cells which overexpressed lsadh produced (R)-form chiral alcohols from ketones using 2-propanol as a hydrogen donor with the highest level of productivity ever reported and enantiomeric excess (e.e.).

Enantioselective bioreductive preparation of chiral halohydrins employing two newly identified stereocomplementary reductases

Two robust stereocomplementary carbonyl reductases (DhCR and CgCR) were identified through rescreening the carbonyl reductase toolbox. Five reductases were returned through the activity and enantioselectivity assay for α-chloro-1-acetophenone and ethyl 4-chloro-3-oxo-butanate (COBE). Three reductases were stable at elevated substrate loading. Enzymatic characterization revealed that DhCR and CgCR were more thermostable. As much as 330 g COBE in 1 L biphasic reaction mixture was reduced to (S)- and (R)-3-hydroxy-4-chlorobutyrate by DhCR and CgCR (coexpressed with glucose dehydrogenase), with 92.5% and 93.0% yields, >99% ee, and total turnover numbers of 53800 and 108000, respectively. Six other α-halohydrins were asymmetrically reduced to optically pure forms at a substrate loading of 100 g L-1. Our results indicate the potential of these two stereocomplementary reductases in the synthesis of valuable α-halohydrins for pharmaceuticals. This journal is

Stereochemical Control of Yeast Reductions. 5. Characterization of the Oxidoreductases Involved in the Reduction of β-Keto Esters

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Method for continuously preparing (R)-4-halo-3-hydroxy-butyrate by using micro-reaction system

The invention belongs to the technical field of chemical engineering, and particularly relates to a method for continuously preparing (R)-4-halo-3-hydroxy-butyrate by using a micro-reaction system. Asubstrate solution containing halogenated acetoacetate and a biological catalytic solution are continuously subjected to an enzyme-catalyzed asymmetric reduction reaction in the micro-reaction systemcomposed of a micro-mixer, a micro-channel reactor and a pH regulator so as to obtain the (R)-4-halo-3-hydroxy-butyrate. Compared with the prior art, the method has the advantages that: the reaction time is only a few minutes, the yield of the product (R)-4-halo-3-hydroxy-butyrate is more than 95 percent, the process is continuous, the automation degree is high, the efficiency is high, the technological process is simple and convenient to operate, and the industrial production is easy.

Method for preparing 3 -hydroxy -4 -chlorobutyric acid ethyl ester

The invention discloses a method for preparing 3 -hydroxy -4 -chlorobutyric acid ethyl ester. The method comprises 4 - chloroacetoacetate as a raw material, methanol as a solvent and sodium borohydride as a reducing agent. The methanol is concentrated to recycle after the reaction is finished. The residue is added with methanol, hydrogen chloride gas is introduced to pH=2 - 3 filtration desalination, and the hydrogen chloride - methanol system is recycled. The residue was distilled under reduced pressure to give ethyl 3 -hydroxy -4 -chlorobutyric acid ethyl ester. The sodium borohydride is low in use amount, no by-product peak occurs, and the yield reaches 83 - 87%. The methanol and hydrogen chloride - methanol two solvent systems are separately recycled, so that the use of a low-boiling-point solvent is avoided. The synthetic process is low in cost, high in yield and environmentally friendly, and can be used for industrial large-scale production.