JP2605538B2 - Chiral derivatization reagent and separation analysis method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a derivatization reagent used for separating and analyzing a hydroxyl group-containing enantiomer, and a method for separating and analyzing a compound for each enantiomer using this reagent.

[0002]

2. Description of the Related Art Several methods have been considered for separating and analyzing optical isomers of hydroxyl group-containing compounds, especially alcohols. There is a method of reacting with a reagent to convert to a derivative and analyzing the derivative. As the compound derivatizing reagent, 1-phenylethyl isocyanate, trifluoroacetylprolyl chloride and the like are considered,
These reagents have low reaction sensitivity to the compounds. Furthermore, the obtained compound derivative was inadequate for pretreatment of chromatography for separation analysis, such as insufficient analytical sensitivity and solubility of the compound derivative by optical isomerism. Also, these reagents were expensive and never satisfactory.

[0003]

SUMMARY OF THE INVENTION The present invention provides a chiral derivatization reagent for an enantiomer of a hydroxyl group-containing compound containing an alcohol, and reacts the reagent with an enantiomer of a hydroxyl group-containing compound to obtain a highly sensitive enantiomer. It provides a method of separating and analyzing.

[0004] Thus, the present invention provides (+) or (-)-
It is intended to provide a chiral derivatization reagent comprising 2-methyl-1,1′-binaphthalene-2′-carbonylnitrile.

A structural feature of this reagent is that two planar bulky naphthalene nuclei have a cyanocarbonyl group (--COCN) which easily reacts with a hydroxyl group, and a novel, not yet described in the literature. Compound.

In the present invention, the reagent can be manufactured as follows. (I): Formula

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A compound of formula (II) wherein R and R ′ are C _1-4 alkyl groups is reduced to obtain a compound of formula (II):

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Wherein R ′ is the same as defined above, and then the compound of formula (II) is halogenated to form a compound of formula
(III):

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Wherein X is a halogen and R 'is the same as defined above, which is dehalogenated and esterified to give a compound of the formula (IV):

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The formula (IV) is converted into a nitrile to obtain the formula (V):

Embedded image And optically resolved at the stage of formula (IV) or (V) to give (+) or (−)-2-methyl-1,
1′-Binaphthalene-2′-carbonylnitrile can be obtained.

That is, the reagent of the formula (V) comprises (i) reduction of an ester group of R, (ii) subsequent halogenation of a hydroxyl group,
It is produced through four steps: (iii) dehalogenation of an alkyl halide and esterification of R ′, and (iv) cyanocarbonylation.

The reaction reagents used in these manufacturing processes may be those conventionally used, and the reaction conditions may be set according to the reaction reagents used.

For example, as the reducing agent used in the step (i), there may be mentioned hydride compounds such as lithium aluminum hydride and sodium borohydride, and organometallic compounds such as lithium tri-tert-butoxy-aluminum aluminum hydrogen.

The halogenation in the step (ii) can be carried out by using a hydrogen halide, a phosphorus halide or the like in the presence of an acid.

In the step (iii), the step (i)
The dehalogenation of R is performed by using the reagent used in the above. Next, esterification of R ′ is performed. For example, the above-mentioned metal hydride is mentioned for dehalogenation, and the strong acid strong alkali etc. are mentioned for ester decomposition of R '.

In the step (iv), a metal cyanide salt or an ammonium cyanide salt may be used. Reaction intermediates include (+)-coordinate and (-)-coordination products. However, during the synthesis, it is not necessary to separate and synthesize them, and it is better to separate them in the later reaction stage. That is, when the compound of the formula (V) is synthesized, it is desirable that the compound of formula (V) is separated for each (+) (−) coordination, if desired.

The separation may be effected by a fractional recrystallization method using a suitable solvent such as a lower alcohol.

In still another embodiment, (+) or (-)-2-methyl-1,1'-binaphthalene-2'-
It is intended to provide a chiral derivatization reagent comprising carbonyl nitrile. By using this reagent, an enantiomer of a compound containing a hydroxyl group and having an asymmetric carbon at the bonding position is reacted with this reagent in the presence of an organic base to form a corresponding diastereomer, which is then chromatographed. And separating each (+) or (-) enantiomer and subjecting it to fluorescence analysis.

The reaction between the reagent of the present invention and an enantiomer of a hydroxyl group-containing compound is as follows.

[0020]

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The reagent according to the present invention does not emit fluorescence in an unreacted state, but emits fluorescence only after reacting with a hydroxyl group.
This indicates that the reaction product can be directly subjected to fluorescence analysis without removing excess reagent from the reaction product.
Furthermore, this reaction is completed under a mild condition and in a short time, and the reaction product and the reagent are not racemized even if the reaction time is extended.

The reagent according to the present invention reacts very specifically with primary alcoholic hydroxyl groups and secondary alcoholic hydroxyl groups. It does not react with sterically hindered secondary or tertiary alcoholic hydroxyl groups. A specific example is described below. The reaction with lower alcohols such as methanol and ethanol, primary and secondary amines is completed at room temperature.

This active ingredient can be used alone, but is preferably dissolved in an aprotic organic solvent to form a reagent. In particular, when the compound of the formula (V) is used as a fluorescent reagent, the presence of an organic base results in a favorable reaction with the test sample, so that it is preferable to add an organic base to the reagent.

Specific examples of the aprotic organic solvent include:
Chloroform, acetonitrile, benzene, ethyl acetate, tetrahydrofuran, acetone and the like can be mentioned.
Of these, acetonitrile is most preferred. Examples of the organic base include tertiary alkylamines such as triethylamine and trimethylamine.

The ratio of the aprotic organic solvent to the organic base is preferably about 1: 1. The concentration of the compound of the formula (V) in these mixtures is not particularly limited, but is, for example, 0.1 to 1%.

Since the fluorescent reagent does not emit fluorescence in the unreacted state, it may be sufficiently used by using an excess amount of the test sample.

Accordingly, the test sample is reacted with the reagent of the present invention in a pre-column in advance, subjected to high performance liquid chromatography, separated into enantiomers, and detected with a fluorometer. The generated fluorescence has an excitation wavelength of 342 nm and an irradiation wavelength of 420 nm, and the detection limit is 200 pg when high performance liquid chromatography is used.

[0028]

The present invention will be described in more detail with reference to synthesis examples and analysis examples.

Synthesis Example 2-Thimer-1,1'-binaphthalene-2'-carboni
This Synthesis Example Synthesis of Runitoriru intermediate product a compound of formula (I) as starting material (formula (II), (III), (IV)) of the following: illustrates a method of synthesizing the reagents of the present invention through the It goes through the process shown by the chemical formula.

[0030]

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(I) methyl 2-hydroxymethyl-1,
1'-Binaphthalene-2-2'-carboxylate dimethyl 1,1'-binaphthalene-2,2'-dicarboxylate (2.8 g) (J. Chem. Soc., 195)
To a mixed solution of anhydrous benzene (75 ml) -anhydrous ether (75 ml) prepared by the method described in US Pat. No. 5,1242), tri-tert-butoxy-lithium aluminum hydride (LiAl (tert-BuO) ₃ H) (8 g) was added.
Added in small portions over time. After being acidified by adding 5% hydrochloric acid under ice cooling, the organic layer was separated and dried over anhydrous sodium sulfate. The organic layer was concentrated, and the residue was subjected to silica gel (50
Purified by column chromatography using g). The fraction eluted with hexane / ethyl acetate (4: 1) was recrystallized from hexane / acetone to obtain 1 g of the compound of the formula (II) as colorless plate crystals. Physical properties of the obtained compound were as follows. 117.5-118.5 ° C. NMR (CDCl ₃ ) δ: 3.52 (3H, s, —OC
_{H 3), 4.32 (2H,} s, -CH 2 -O -), 6.
84-8.02 (12H, m, Ar-H). Elemental analysis: _{(C 23 H} 18 as _{O 3)} Calculated: Carbon 80.7%, hydrogen 5.26%, Found: Carbon 80.2
%, Hydrogen 5.28%

[0032](Ii) methyl 2-bromomethyl-1,
1'-binaphthalene-2'-carboxylate The methyl 2-hydroxymethyl-1, obtained in the above (i),
1'-binaphthalene-2'-carboxylate (2g)
30% hydrogen bromide / acetic acid solution in acetic acid (10 ml)
(5 ml) and stirred at 50 ° C. for 10 minutes. reaction
The liquid was poured into ice to precipitate crystals, which were collected by filtration. This crystal is
Purified by column chromatography on Rica gel,
The fraction eluted with sun / ethyl acetate (30: 1) was extracted with hexane / vinegar
It was recrystallized from ethyl acid. Compound 2.2 of formula (III)
g were obtained as needle crystals. The physical properties of the obtained compound are as follows:
It was as follows. 137-138 ° C NMR (CDCl₃) Δ: 3.46 (3H, s, -OC
H₃), 4.10 (1H, d, J = 14 Hz, -CHB)
r), 4.24 (1H, d, J = 14 Hz, -CHB
r), 6.90-8.20 (12H, m, Ar-H). Elemental analysis: (C₂₃H₁₇Calculated as OBr): carbon
68.1%, hydrogen 4.20%, measured value: carbon 68.2
%, Hydrogen 4.27%

(Iii) 2-methyl-1,1′-binaph
Taren-2'-carboxylic acid Methyl 2-bromomethyl-1,1 'obtained in (ii) above
-Binaphthalene-2'-carboxylate (1.9 g)
Was dissolved in dimethylsulfoxide (10 ml), and sodium borohydride (0.4 g) was added thereto.
For 15 minutes. The reaction solution was poured into ice water, acidified with concentrated hydrochloric acid to precipitate crystals and collected by filtration. The obtained crystals were purified by column chromatography on silica gel, and the fraction eluted with hexane / ethyl acetate (10: 1) was recrystallized from methanol. The methyl ester (1.4 g) of the compound of the formula (IVa) was obtained as colorless needles, and the physical properties of the obtained ester were as follows. 97-98 ° C NMR (CDCl ₃ ) δ: 2.04 (3H, s, -CH
_{3), 3.44 (3H, s} , -OCH 3), 6.88-
8.12 (12H, m, Ar-H). Elemental analysis: _{(C 23 H} 18 _{O 2)} Calculated values: carbon 84.6%, hydrogen 5.56%, found: 84.6%, hydrogen 5.52% and then the resulting methyl ester in methanol ( 50ml)
A 10% aqueous potassium hydroxide solution (30 ml) was added to the solution, and the mixture was heated under reflux for 3 hours. The reaction solution was poured into ice water, and the precipitated crystals were collected by filtration. The crystals were recrystallized from hexane / ethyl acetate to give the compound of the formula (IVa) as colorless needles, the physical properties of which were as follows. 232-233 ° C NMR (CDCl ₃ ) δ: 1.96 (3H, s, -CH
_{3), 6.80-8.12 (12H, m} , Ar-H) Elemental analysis: _{(C 22 H} 16 _{O 2)} Calculated values: carbon 84.6%, hydrogen 5.13%, Found: Carbon 84.3
%, Hydrogen 4.93%

(Iv) 2-methyl-1,1′-binaphtha
Optical resolution of len-2'-carboxylic acid Anhydrous solution was added to a solution of 2-methyl-1,1'-binaphthalene-2'-carboxylic acid (3.3 g) in ethanol (60 ml).
-A solution of brucine (4.1 g) in ethanol (20 ml) was added and left overnight at room temperature. The precipitated crystals are collected by filtration,
Purification was performed by fractional crystallization from ethanol several times. The obtained salt was acidified with 5% hydrochloric acid, and then extracted with ethyl acetate.
The organic layer was dried over anhydrous sodium sulfate, and after the solvent was distilled off, the residue was recrystallized from hexane / acetone to obtain a compound of the formula (IVc) having (-) coordination as colorless needles. It was as follows. Melting point: 229 to 229.5 ° C

[0035]

[Outside 1] Elemental analysis: _{(C 22 H} 16 _{O 2)} Calculated values: carbon 84.6%, hydrogen 5.13%, Found: Carbon 84.3
%, Hydrogen 5.00% The same treatment was carried out for the mother liquor of recrystallization with 1-brucine to obtain a compound of the formula (IVb) having the (+) coordination as colorless needles, the physical properties of which are as follows: there were. Melting point 232-233 ° C

[0036]

[Outside 2] Elemental analysis: measured values: carbon 84.4%, hydrogen 5.10%

(V) 2-methyl-1,1′-binaphthale
Oxalyl chloride (3 ml) was added to a solution of dimethyl- 2'-carbonylnitrile 2-methyl-1,1'-binaphthalene-2'-carboxylic acid (0.5 g) in anhydrous methylene chloride (30 ml), and the mixture was added at room temperature for 2 hours. Stirred. The reaction was concentrated to give a yellow oil. This was dissolved in anhydrous methylene chloride (10 ml), trimethylsilyl cyanide (3 ml) and zinc iodide (1 mg) were added, and the mixture was stirred at room temperature for 2 hours. The reaction was concentrated to give a red oil. The obtained oil was purified by column chromatography on silica gel (5 g), and the fraction eluted with hexane was recrystallized from hexane / petroleum ether. A yellow needle-like compound of the formula (Va) (240 mg) was obtained, and the physical properties were as follows. Melting point 109-110 ° C IR ν _max (CHCl ₃ ): 2240 (C = N), 1
^{660 (C = O) cm -} 1 NMR (CDCl 3) δ: 2.04 (3H, s, -C
_{H 3), 6.72-8.24 (12H,} m, Ar-H) Mass spectrometry ^{m / z: 321 (M +} ) Elemental _{analysis: (C 23 H} 15 as ON) Calculated: Carbon 8
6.0%, 4.71% hydrogen, 4.36% nitrogen, measured:
A (+)-coordinated compound of the formula (IVb) (0.5 g) obtained with 86.0% of carbon, 4.93% of hydrogen, and 3.87% of nitrogen (iv) was treated in the same manner as described above to give yellow. An oily compound of formula (Vb) was obtained, the physical properties of which were as follows:

[0038]

[Outside 3] Elemental analysis: measured values: 85.9% of carbon, 4.73% of hydrogen,
Nitrogen 4.47% In addition, the compound of the formula (IVc) (0.5 g) in the (-) configuration obtained in (iv) was treated in the same manner as described above to obtain a compound of the formula (IVc) as a yellow oil. Its physical properties were as follows.

[0039]

[Outside 4] Elemental analysis: measured values: 85.9% of carbon, 4.73% of hydrogen,
4.47% nitrogen

Analysis Example 3-hydroxyoctanoic acid, 3-hydroxydecanoic acid,
Each of methyl esters of 3-hydroxylauric acid, 3-hydroxystearic acid and mandelic acid was converted to (+)-2-methyl-1,1′- in the presence of triethylamine.
Binaphthalene-2'-carbonylnitrile 2 at 60 ° C
The mixture was quantitatively reacted for 0 minutes to obtain an ester.

The reaction mixture was separated into enantiomers by high performance liquid chromatography. In the high performance liquid chromatography, a 6000A solvent liquid feeder manufactured by Waters equipped with a 650-10LC fluorescence detector manufactured by Hitachi, Ltd. was used, and a Cosmo-sil 5SL column was used as a column. As a mobile phase, a mixed solution of n-pentane / ethyl acetate (30: 1) was sent at a rate of 1.0 ml / min. The separated ester was detected by fluorescence and quantitatively analyzed. The results are shown in the table below.

[0042]

[Table 1]

In the table, k 'is a volume ratio, α is a separation factor, and R is a lysis factor.

As can be seen from the table, it was shown that the reagents of the present invention separated each enantiomer.

By using the reagent of the present invention, the enantiomer of a hydroxyl group-containing compound can be reacted in a precolumn of high performance liquid chromatography, and this reagent does not emit fluorescence by itself, It is understood that fluorescence is emitted only after reacting with, so that fluorescence can be detected without removing the reagent present in excess in the reaction solution.

This reagent can also be applied to the quantitative analysis of drugs, for example, the analysis of fine substances such as β-sympathetic blockers in biological fluids.

Continued on the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical indication location G01N 21/78 G01N 21/78 C 30/06 30/06 E 30/74 30/74 F 31/22 122 31 / 22 122 // C09K 11/06 9280-4H C09K 11/06 Z C07M 7:00

Claims (2)

(57) [Claims] (1) (+) or (−)-2-methyl-1,
Chiral derivatizing reagents consisting of 1'-binaphthalen-2'-carbonyl nitrile. 2. A compound containing a hydroxyl group and having an asymmetric carbon at the bonding position, wherein (+) or (−)-2-methyl-1,1′-binaphthalene-2′-
Reacting the carbonyl nitrile in the presence of an organic base to form the corresponding diastereomer, which is chromatographically separated for each (+) or (-) enantiomer and the enantiomer is analyzed by fluorescence A separation analysis method characterized by the above-mentioned.