KR100650797B1 - Method for preparing optically active cyclopropane carboxamide - Google Patents

Abstract

The present invention relates to a method for preparing a cyclopropane carboxamide optically active material of Chemical Formula 1 using an enzyme.

[Formula 1]

Wherein R ₁ , R ₂ may be the same or different from each other, and hydrogen, substituted or unsubstituted straight or branched C1 to C7 alkyl, substituted or unsubstituted straight or branched C1 to C7 alkenyl, benzyl , Substituted or unsubstituted C3 to C7 cycloalkyl, substituted or unsubstituted arylalkyl, or substituted or unsubstituted heteroarylalkyl.

Description

Process for Preparing Chiral Substituted Cyclopropane Carboxamide

The present invention relates to a method for preparing a cyclopropane carboxamide optically active substance using an enzyme.

Substituted cyclopropane carboxylic acids, in particular 2,2-dimethylcyclopropanecarboxylic acid with optical activity, are used as raw materials for dihydropeptidase I inhibitors and pyresteroid-based pesticides with very low toxicity to mammals. 1,260,847), the key intermediates used in Cilastatin (European Patent No. 48,301, European Patent No. 48,025) and optical splitting agents to prevent carbapenem antibiotics from being broken down in the kidneys. It is a chiral building block with an industrial meaning.

In the existing manufacturing process, an ester is prepared using L-menthol or (S) -mandelic acid ester having photoactive amines or hydroxy groups, and is prepared by repeated recrystallization and the desired (S) through fermentation process. It can be divided into the process of manufacturing the product of the foam. Both processes are industrially constrained because of the several disadvantages that must involve low optical purity of the product, low yield, use of expensive optical splitting reagents, and repetitive recrystallization processes.

In addition, U.S. Patent No. 4,542,235 discloses the use of various substituted photoactive diphenylethylamines as optical splitting agents to prepare chiral (S) -dimethyl cyclopropane carboxylic acid, but the substituted chiral diphenylethylamines used in the present invention. Is an expensive reagent that is generally difficult to obtain, and it has the disadvantage of not only increasing the manufacturing cost but also recrystallization twice or more, and using excessive solvent when recrystallization. Patent No. 4,487,956 has a disadvantage in that a useful method or post-treatment process is very complicated and relatively expensive L-menthol should be used in view of high yield and high optical purity. U.S. Patent No. 5,166,417 discloses optical splitting by preparing a diastereomer using photoactive L- (3-methoxyphenyl) ethylamine and then recrystallizing the same. As well as use, the yield was very low, at a level of 21% and the optical purity of the prepared (S) -dimethyl cyclopropane carboxylic acid was 93% or less, thus lacking commercial utility.

Japanese Patent Laid-Open Publication No. 80-051023 discloses a method for preparing (S) -dimethyl cyclopropane carboxylic acid using an optical splitting method using quinine, but quinine is very expensive and may not be supplied stably. In addition, the yield was low. In addition, British Patent Publication No. 1260847 discloses a method of using D- or L-phenethylamine for optical splitting, but the optical purity of (S) -dimethyl cyclopropane carboxylic acid prepared by the above method is only 49%. In addition, the yield was low, there was a problem that the industrial usefulness falls.

In addition, U.S. Patent No. 5,243,070 discloses that dimethylcyclopropane carboxylic acid is reacted with chiral mandelic acid methyl ester to prepare dimethylcyclopropane carboxylic acid ester racemate, which is then optically divided by recrystallization method, and then hydrolyzed to (S)- A method of preparing dimethylcyclopropanecarboxamide is disclosed by preparing a dimethylcyclopropane carboxylic acid and then performing a resolution process of separating a chiral separation reagent and an isomer, but the (S) -mandelic acid methyl ester used at this time is expensive. It is a reagent of and has the disadvantage of repeating recrystallization three or more times to increase optical purity.

Most recently published methods using the fermentation process US Patent No. 5,273,903, US Patent No. 5,360,731 method is a selective decomposition reaction of 2,2-dimethylcyclopropane carboxamide racemate using a variety of microorganisms Although a method for preparing (S) -dimethylcyclopropane carboxamide is proposed using the above-described invention, the present invention not only has two days to incubate microorganisms in advance, but also has a complicated reaction and separation process, The problem is that the concentration falls to 2%.

On the other hand, International Patent Publication No. 2004/5241 discloses a method for preparing (S) -dimethylcyclopropane carboxylic acid by optical splitting reaction using esterase, but the optical splitting by enzyme is applied to compounds of specific structures. Not all enzymes have the effect of optical splitting, but the corresponding optical splitting is performed only by a specific enzyme, and furthermore, even if the lipase used for the optical splitting, depending on its source, the kind and function of the compound Based on the difference in the kind and reactivity of the optical isomer, the esterase is not only confused with the category of the microorganism but also the specific examples of the esterase being used are described in the Examples of the specification. (S) -dimethylcyclopropane carboxylic acid substantially without enzyme It is difficult to say that optical splitting is known.

Korean Patent Publication No. 10-2004-0004744 discloses a dimethylcyclopropane carboxylic acid ester racemate by reacting dimethylcyclopropane carboxylic acid with an alcohol, and then (S) -dimethylcyclopropane carbon by biological resolution using microorganisms. Acid and (R) -dimethylcyclopropane carboxylic acid were prepared, and the (S) -dimethylcyclopropane carboxylic acid prepared above was subjected to addition reaction with various chlorination reagents and ammonia to (S) -dimethylcyclopropanecarboxamide. Methods of preparing are known. However, since the (S) -dimethylcyclopropane carboxylic acid and (R) -dimethylcyclopropane carboxylic acid coexist in the reaction solution, the above-mentioned method must undergo an extraction step of separately separating (S) -dimethylcyclopropane carboxylic acid. Due to the extraction process, a large amount of organic solvent must be used, and an amide preparation reaction in which (S) -dimethylcyclopropane carboxylic acid, chlorination reagent and ammonia are reacted to prepare (S) -dimethylcyclopropanecarboxamide Since the process has to go through a long process, there is a problem that the yield is lowered. In addition, the hydrolysis reaction of the ester compound insoluble in water caused a problem that the enzyme is agglomerated during the reaction.

The inventors of the present invention are specific to the substituted cyclopropane carboxylic acid ester of (S) -form only when the cyclopropane carboxylic acid ester racemate is reacted with an lipase derived from Candida anthracica as an enzyme in an organic solvent in which ammonia gas is dissolved. The reaction was carried out to prepare a substituted cyclopropane carboxamide of (S) -form and a substituted cyclopropane carboxylic acid ester of (R) -form in the reaction solution. Accordingly, an object of the present invention is to provide a conventional optical activity. (S) -cyclopropane carboxamide derivatives can be converted to high optical purity and high yield by reacting hydrolytic enzymes at high concentrations without using expensive optical splitting agents such as amines and L-menthols or complex fermentation processes. It is to provide a new manufacturing method that is economical.

The present invention relates to a novel method for preparing chiral substituted cyclopropane carboxamide isomers using enzymes. Specifically, (1) reacting the cyclopropane carboxylic ester racemate of Formula 3 with a lipase derived from Candida anthtacica under a constant reaction temperature in an organic solvent in which ammonia gas is dissolved, and (2) And a method for preparing cyclopropane carboxamide and cyclopropane carboxylic acid ester, which are optically active materials comprising the step of separating the cyclopropane carboxamide compound and the (R) -cyclopropane carboxylic acid ester compound of the formula (2).

[Formula 1]

[Formula 2]

[Formula 3]

[R ₁ , R ₂ of the above Chemical Formulas 1 to 3 may be the same or different from each other, hydrogen, substituted or unsubstituted straight or branched C1 to C7 alkyl, substituted or unsubstituted straight or branched C1 to C7 Alkenyl, benzyl, substituted or unsubstituted C3 to C7 cycloalkyl, substituted or unsubstituted arylalkyl or substituted or unsubstituted heteroarylalkyl; R ₃ , R ₄ may be the same as or different from each other, and are hydrogen, substituted or unsubstituted straight or branched C1 to C7 alkyl, substituted or unsubstituted straight or branched C1 to C7 alkenyl, benzyl, substituted Or substituted or unsubstituted C3 to C7 cycloalkyl, substituted or unsubstituted arylalkyl, or substituted or unsubstituted heteroarylalkyl; R ₅ is C1 to C7 linear or branched alkyl, C1 to C7 substituted with halo compound, C1 to C7 straight or branched alkyl or substituted or unsubstituted straight or branched C1 to C7 alkoxy group substituted C1 to C7 straight chain Or branched alkyl.]

Hereinafter, the present invention will be described in detail.

When the cyclopropane carboxylic acid ester racemate of the formula (3) of the present invention is reacted with a lipase enzyme in an organic solvent in which ammonia gas is dissolved, while maintaining the reaction temperature, only the substituted cyclopropane carboxylic acid ester of (S) -form is specific. In the reaction solution, the substituted cyclopropane carboxamide of (S) -form and the substituted cyclopropane carboxylic acid ester of (R) -form exist, and the (S) -form substitution is carried out through a simple separation process. The cyclopropane carboxamide compound may be separated from the substituted cyclopropane carboxylic acid ester of the (R) -form. This is due to the lipase derived from Candida anthracica specifically reacting the compound of the (S) -cyclopropane carboxylic acid ester nucleus structure.

As an enzyme used for optical splitting, lipases are very broad, including lipases from Candida cylindracea, Pseudomonas sp., Candida rugosa, or Candida antarctica. Depending on the source, there is a difference in the kind of the compound, the kind of optical isomers and the reactivity. In most cases, the lipase derived from Candida antarctica can obtain very high conversion and high optical purity in the optical splitting reaction by enzyme. .

Optical splitting by enzyme reaction proceeds as shown in Scheme 1 below.

Scheme 1

As shown in Scheme 1, the cyclopropane carboxylic ester racemate 3 can be easily prepared by esterification of the cyclopropane carboxylic acid racemate 4 with various alcohols.

Similar to the conventional esterification reaction, cyclopropane carboxylic acid racemate (4) was added to an organic solvent and thionyl chloride (SOCl ₂ ) was added dropwise to prepare a compound substituted with a leaving group such as acyl halide. 2-chloroethanol, 2,2-dichloroethanol, 2,2,2-trichloroethanol, 2-fluoroethanol, 2,2-difluoroethanol, 2,2,2-trifluoroethanol, 2- in the reaction mixture Cyclopropane carboxylic acid ester through the process of addition of one alcohol derivative selected from bromoethanol, 2,2-dibromoethanol, 2,2,2, -tribromoethanol or 2-methoxyethanol The racemate 3 can be produced in high yield of at least 85%. A lipase derived from Candida anthracica is added as an enzyme to the prepared cyclopropane carboxylic acid ester racemate (3), and optical split reaction is performed in an organic solvent in which ammonia gas is dissolved.

The organic solvent may be an alcohol solvent selected from methanol, ethanol, propanol, isopropanol, butanol, isoamyl alcohol, tert-butanol, pentanol, nucleic acidol, heptanol, and octanol; Oxane solvents selected from 1,4-dioxane and trioxane, amide solvents selected from diethylformamide, dimethylformamide, aromatic solvents selected from dimethyl sulfoxide, benzene, toluene, xylene; It is characterized by one or two or more kinds selected from non-polar solvents selected from hexane, heptane, octane, cyclohexane.

Optical splitting reaction by specific enzymatic reaction by a lipase derived from Candida anthracica according to the present invention can be performed within the range of the carboxylic acid ester compound having a cyclopropane carboxylic acid nucleus structure. Substituents may be substituted, but R ₁ , R ₂ may be the same or different from each other, and hydrogen, substituted or unsubstituted straight or branched C1 to C7 alkyl, substituted or unsubstituted straight or branched C1 to C7 Alkenyl, benzyl, substituted or unsubstituted C3 to C7 cycloalkyl, substituted or unsubstituted arylalkyl, or substituted or unsubstituted heteroarylalkyl is preferably selected, and R ₁ , R ₂ are the same or different from each other. Methyl, ethyl, n-propyl, i-propyl, n-butyl, n-pentyl, n-hexyl, fluoromethyl, It is preferred to achieve the object of the production process according to the invention when selected from difluoromethyl or trifluoromethyl, more preferably when both R ₁ and R ₂ are methyl.

In addition, the most significant influence in the optical splitting reaction by a specific enzyme reaction by lipase derived from Candida anthracica is the property of the R ₃ to R ₅ substituents of the cyclopropane carboxylic ester racemate, and the enzyme according to the present invention. The range of ester substituent that can be reacted may be the same or different from each other, R ₃ , R ₄ , hydrogen, substituted or unsubstituted straight or branched C1 to C7 alkyl, substituted or unsubstituted straight or branched C1 To alkenyl, benzyl, substituted or unsubstituted C3 to C7 cycloalkyl, substituted or unsubstituted arylalkyl, or substituted or unsubstituted heteroarylalkyl, R ₅ is C1 to C7 straight or branched chain and is selected from alkyl of appropriate feet that are electron rich atoms is substituted in position 1 of the R ₅ substituent present In the enzyme reaction in accordance with, it is preferred to improve the optical purity, and thus R ₅ is halo compound substituted C1 to C1 to an alkoxy group substituted with a C7 of the straight-chain or alkyl or an optionally substituted straight or branched chain C7 to Preferably selected from C1 to C7 linear or branched alkyl. In particular R ₃ , R ₄ are hydrogen, R ₅ is fluoromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, bromomethyl, dibromomethyl, tribromomethyl Most preferably, methoxymethyl or ethoxymethyl.

The enzyme used in the optical splitting reaction by the specific enzyme reaction by the enzyme is commercialized and can be easily obtained and used as a lipase derived from Candida antarctica. The concentration of the lipase derived from Candida anthracica in the reaction system is preferably 1 to 30% by weight based on cyclopropane carboxylic acid ester racemate, which is about 5% by weight, and more preferably about 5% by weight of the enzyme. It is preferable to use immobilized for economics.

The optical splitting reaction of cyclopropane carboxylic acid by a specific enzyme reaction by lipase derived from Candida anthracica according to the present invention is carried out while keeping the reaction temperature constant, wherein the reaction temperature is preferably 10 to 80 ° C. Considering the optical purity, the reaction temperature is most preferably 20 to 45 ° C.

The concentration of cyclopropane carboxylic acid ester racemate used as a substrate in the optical splitting reaction by enzyme is preferably 3% to 70%, and 5% to 40% is preferable in consideration of process efficiency and the like.

The method according to the present invention can be obtained by separating the optically active materials cyclopropane carboxamide and cyclopropane carboxylic acid ester by a simple post-treatment process after the optical splitting reaction by an enzyme-specific enzyme reaction.

The reaction mixture was filtered to recover the enzyme, and the organic solvent and the low boiling organic substance were recovered by distillation from the filtrate to obtain (S) -2,2-dimethylcyclopropane carboxamide, and the obtained (S) -2, To increase the purity and optical purity of 2-dimethylcyclopropane carboxamide, it is recrystallized and purified under methanol.

The enzyme used in the enzyme reaction can be washed again after separation by means of a filter or the like after the completion of the reaction.

Hereinafter, the present invention will be described in more detail with reference to the following examples. The scope of the present invention is not limited by these examples.

Preparation Example 1 Preparation of Substituted Cyclopropane Carboxylic Acid 2,2,2-Trifluoroethyl Ester

500 ml of methylene chloride and 228 g of dimethylcyclopropane carboxylic acid were added to the reactor, mixed well at room temperature, and 236 g of thionyl chloride (SOCl ₂ ) was slowly added dropwise while maintaining the temperature at 20 ° C. After further stirring at room temperature for 1 hour, 190 g of 2,2,2-trifluoroethanol was slowly added dropwise and stirred at room temperature for 2 hours. After washing with saturated sodium carbonate (Na ₂ CO ₃ ) solution, drying with anhydrous sodium sulfate (Na ₂ SO ₄ ) and distilling under reduced pressure to remove the organic solvent, the title dimethylcyclopropane carboxylic acid 2,2,2-trifluoroethyl 340 g (87% yield) of ester racemate compound were recovered.

Preparation Example 2 to 5 Preparation of Dimethylcyclopropane Carboxylic Acid Ester Racemate

Alcohol type was 2,2,2-trichloroethanol (preparation example 2), 2-methoxyethanol (preparation example 3), 2-bromoethanol (preparation example 4), 2-chloroethanol (preparation example 5) Differently, various kinds of dimethylcyclopropane carboxylic acid ester racemates were prepared in the same manner as in Preparation Example 1. The results are shown in Table 1.

TABLE 1

Example 1 Enzyme Screening

50 mg (5%) of dimethylcyclopropane carboxylic acid 2,2,2-trifluoroester racemate prepared in Preparation Example 1 in 1 ml of t-butanol saturated with ammonia gas, Candida anthac as enzyme 2.5 mg of candida anthacdica type B lipase, a lipase derived from tika, was reacted at 30 ° C. for 20 hours, and 0.2 ml of the reaction solution was measured for optical purity using gas chromatography equipped with a chiral column.

Comparative Example 1 to Comparative Example 15 Comparison of Stereospecific Enzyme Reactions According to Enzymes

Conversion rate and optical properties of the (S) -dimethylcyclopropane carboxamide optical isomer according to the Candida anthacdica type B lipase, a lipase derived from Candida anthracica, an enzyme used in the preparation method according to the present invention, and other enzymes In order to compare the purity, the reaction was carried out under the same conditions as in Example 1 except for changing the types of enzymes as described in Table 2.

TABLE 2

As can be seen in Table 2, the enzyme was screened with 2,2-dimethylcyclopropane carboxylic acid 2,2,2-trifluoroethyl ester racemate as a substrate. Only showed the production of (S) -dimethylcyclopropane carboxamide optical isomer with high optical purity of industrial usefulness, and other lipases, proteases and esterases did not proceed at all, and thus Significant effects of the candida antarctica-derived lipase, an enzyme of the preparation method, as a stereospecific enzyme could be confirmed.

Example 2 Enzymatic Reaction of 2,2-Dimethylcyclopropane Carboxylic Acid 2,2,2-Trichloroethyl Ester

In order to compare the enzyme reaction for each type of substituted alcohol by the method of Example 1 except for using the 2,2-dimethylcyclopropane carboxylic acid 2,2,2-trichloroethyl ester prepared in Preparation Example 2 (S ) -2,2-dimethylcyclopropane carboxamide optical isomer was prepared.

Example 3 Enzymatic Reaction of 2,2-Dimethylcyclopropane Carboxylic Acid 2-methoxyethyl Ester

In order to compare the enzyme reaction for each type of substituted alcohol by the method of Example 1 except for using the substrate 2,2-dimethylcyclopropane carboxylic acid 2-methoxyethyl ester prepared in Preparation Example 3 (S) -2, 2-Dimethylcyclopropane carboxamide optical isomer was prepared.

Example 4 Enzymatic Reaction of 2,2-Dimethylcyclopropane Carboxylic Acid 2-bromoethyl Ester

In order to compare the enzyme reaction for each type of substituted alcohol by the method of Example 1 except for using the substrate 2,2-dimethylcyclopropane carboxylic acid 2-bromoethyl ester prepared in Preparation Example 4 (S) -2, 2-Dimethylcyclopropane carboxamide optical isomer was prepared.

Example 5 Enzymatic Reaction of 2,2-Dimethylcyclopropane Carboxylic Acid 2-Chloroethyl Ester

In order to compare the enzyme reaction for each type of substituted alcohol by the method of Example 1 except for using the 2,2-dimethylcyclopropane carboxylic acid 2-chloroethyl ester prepared in Preparation Example 5 as a substrate (S) -2,2 -Dimethylcyclopropane carboxamide optical isomer was prepared.

Table 3 shows the results of the enzymatic reactions of the substituted alcohols of Examples 2 to 5.

TABLE 3

Example 6 Preparation of (S) -2,2-dimethylcyclopropane carboxamide

After dissolving 10 g of 2,2-dimethylcyclopropane carboxylic acid 2,2,2-trifluoroethyl ester racemate in 100 ml of t-butanol and maintaining 40 ° C, ammonia gas was flowed for 40 minutes and ammonia gas was added to the mixed solution. It was allowed to saturate. While maintaining the temperature as it is, 2 g of Candida anthacdica type B lipase was added to the mixed solution and stirred at a constant speed to react. After completion of the reaction, the reaction mixture was filtered to recover the enzyme, and the organic solvent and the low boiling point organics were recovered by distillation to obtain (S) -2,2-dimethylcyclopropane carboxamide. The titled (S) -2,2-dimethylcyclopropane carboxamide (yield) of the white powder purified by recrystallization in methanol in order to increase the purity and optical purity of the obtained (S) -2,2-dimethylcyclopropane carboxamide. : 40%, optical purity: 99%) was obtained.

The preparation method according to the present invention uses (S) -cyclopropane carcopy by reacting the hydrolase at high concentration without using expensive optical splitting agents such as amines or L-menthol having conventional optical activity or complex fermentation process. The medi derivative has the advantage of providing a new manufacturing method of high economic purity, high yield industrially economical.

Claims (7)

(1) reacting the cyclopropane carboxylic ester racemate of Formula 3 with a lipase derived from Candida anthracica under a constant reaction temperature in an organic solvent in which ammonia gas is dissolved; (2) separating the (S) -cyclopropane carboxamide compound of Formula 1 and the (R) -cyclopropane carboxylic ester compound of Formula 2; Method for producing a cyclopropane carboxamide and cyclopropane carboxylic acid ester which is an optically active material comprising a. [Formula 1]

[Formula 2]

[Formula 3]

[R ₁ , R ₂ of the above Chemical Formulas 1 to 3 may be the same or different from each other, hydrogen, substituted or unsubstituted straight or branched C1 to C7 alkyl, substituted or unsubstituted straight or branched C1 to C7 Alkenyl, benzyl, substituted or unsubstituted C3 to C7 cycloalkyl, substituted or unsubstituted arylalkyl or substituted or unsubstituted heteroarylalkyl; R ₃ , R ₄ may be the same as or different from each other, and are hydrogen, substituted or unsubstituted straight or branched C1 to C7 alkyl, substituted or unsubstituted straight or branched C1 to C7 alkenyl, benzyl, substituted Or substituted or unsubstituted C3 to C7 cycloalkyl, substituted or unsubstituted arylalkyl, or substituted or unsubstituted heteroarylalkyl; R ₅ is C1 to C7 linear or branched alkyl, C1 to C7 substituted with halo compound, C1 to C7 straight or branched alkyl or substituted or unsubstituted straight or branched C1 to C7 alkoxy group substituted C1 to C7 straight chain Or branched alkyl.] The method of claim 1, R ₁ , R ₂ may be the same or different from one another and selected from methyl, ethyl, n-propyl, i-propyl, n-butyl, n-pentyl, n-hexyl, fluoromethyl, difluoromethyl or trifluoromethyl Method for producing cyclopropane carboxamide and cyclopropane carboxylic acid ester, characterized in that the optically active material. The method of claim 1, R ₃ , R ₄ are all hydrogen, R ₅ is fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, bromomethyl, dibromomethyl, tribromomethyl, methoxy A process for preparing cyclopropane carboxamide and cyclopropane carboxylic acid ester, which are optically active materials, characterized in that selected from methyl or ethoxymethyl. The method of claim 3, wherein A method for producing cyclopropane carboxamide and cyclopropane carboxylic acid esters, wherein R ₁ and R ₂ are both methyl. The method of claim 1, The organic solvent is an alcohol solvent selected from methanol, ethanol, propanol, isopropanol, butanol, isoamyl alcohol, tert-butanol, pentanol, nucleic acidol, heptanol, and octanol; Oxane solvents selected from 1,4-dioxane and trioxane; Amide solvents selected from diethylformamide and dimethylformamide; Aromatic solvents selected from dimethyl sulfoxide, benzene, toluene, xylene; A non-polar solvent selected from hexane, heptane, octane and cyclohexane; one or two or more selected from the group consisting of cyclopropane carboxamide and cyclopropane carboxylic acid ester. The method of claim 1, The reaction temperature is 10 to 80 ℃ method for producing cyclopropane carboxamide and cyclopropane carboxylic acid ester, which is an optically active material. The method according to any one of claims 1 to 6, A method for producing cyclopropane carboxamide and cyclopropane carboxylic acid esters, which are optically active substances, wherein the lipase derived from Candida anthracica is Candida anthracica type B lipase.