JPH0327550B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is based on the following general formula (), [However, m is 3 or 4, and R is

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[Formula] (where R ₁ , R ₂ , R ₃ are hydrogen atoms, halogen atoms,
It is a Schiff base type biscrown ether represented by the following formula: different or similar atoms or groups selected from a nitro group, an alkyl group, an alkoxy group, and a phenyl group. Conventionally, there has been a demand for organic compounds that selectively coordinate with potassium salts, and the representative research has focused on macrocyclic polyether compounds. Many studies have been made to develop macrocyclic polyethers for the above purpose. However, most of them did not have sufficient selectivity. It has only been reported that a compound represented by the following general formula exhibits excellent selectivity. (However, n is a positive integer greater than or equal to 1) (However, n is a positive integer greater than or equal to 1) (However, n is a positive integer of 1 or more.) However, the production of any of the above compounds (A), (B), and (C) requires multi-step reaction operations, and each reaction However, it had the disadvantage of requiring complicated purification operations. Furthermore, it has been reported that the synthesis reaction of compound (C) needs to be carried out under extremely dilute conditions to avoid side reactions. Furthermore, since all of these compounds (A), (B), and (C) are highly hydrophilic, when used in applications that require long-term stability, such as potassium electrodes, elution may occur, making long-term use difficult. The problem was that it was difficult. The present inventors have conducted various studies in order to synthesize a macrocyclic polyether that has excellent selective coordination ability with respect to potassium salts and is hydrophobic. As a result, we succeeded in obtaining a macrocyclic polyether compound with excellent selective coordination ability for potassium salts using a much simpler reaction procedure than those of general formulas (A), (B), and (C). , we have completed the present invention. Furthermore, since the macrocyclic polyether of the present invention has extremely low solubility in water, it has the advantage that it can be suitably used in applications requiring long-term stability such as potassium electrodes. That is, the present invention is based on the following general formula () [However, m is 3 or 4, and R is

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[Formula] (where R ₁ , R ₂ , R ₃ are hydrogen atoms, halogen atoms,
It is a Schiff base type biscrown ether represented by the following formula: different or similar atoms or groups selected from a nitro group, an alkyl group, an alkoxy group, and a phenyl group. The Schiff base-type biscrown ether represented by the general formula () of the present invention is a new compound, and can usually be identified as such by the following measurements. (1) Infrared absorption spectrum (IR) Absorption based on cyclic polyether structure is 1270 cm ^-1
It appears strongly near and around 1130cm ^-1 . -CH=N
-An absorption peak derived from the bond appears around 1640 cm ^-1 . (2) ^1H -Nuclear Magnetic Resonance Spectrum When measured in deuterated chloroform solvent using tetramethylsilane as a standard, -CH=N-
The absorption peak derived from H in the group is around 8.3 ppm,
Absorption due to H contained in the aromatic ring is 6.5~
7.9ppm, absorption by H of the methylene group contained in the cyclic ether appears at 3.5 to 4.3ppm, and the relative intensity ratio of these peaks is the ratio of the number of hydrogens bonded to each group calculated from the above general formula (). matches. (3) Mass spectrometry By using the field desorption method (abbreviated as FD) as a means of mass spectrometry, the molecular ion peak of the compound represented by the general formula () of the present invention can be observed. (4) Elemental analysis This is confirmed by comparing the analysis results of carbon, hydrogen, and nitrogen with the theoretical values calculated from the above general formula (). The properties of the compound represented by the general formula () of the present invention will be clear from the explanation of the production method, use, etc., or the results of Examples, which will be described later, but typical properties are as follows. (i) The Schiff base type biscrown ether of the present invention is generally not distillable and it is difficult to obtain a clear boiling point. (ii) It is obtained as a powdery solid by the usual manufacturing method, and is a pale yellow to colored solid at room temperature (25°C), but in the general formula () above, R is

[Formula] When it is a group, it becomes a highly viscous liquid. (iii) The Schiff base type biscrown ether represented by the general formula () is soluble in various organic solvents. For example, it dissolves in methylene chloride, chloroform, benzene, toluene, acetone, tetrahydrofuran, dioxane, dimethylformamide, methanol, etc. at room temperature. Further, it dissolves in ethanol, isopropyl alcohol, etc. under heating, and further dissolves in a small amount in heated hexane and heptane. However, it hardly dissolves in water. Since the above-mentioned properties can be confirmed very easily, it is sufficient to confirm them in advance before use. The method for producing the Schiff base type biscrown ether represented by the general formula () of the present invention is not particularly limited, and any method may be employed. A specific example of an industrially suitable method is as follows. That is, the general formula () (However, m is 3 or 4.) 4-formylbenzocrown ether represented by the general formula () H ₂ N-R-NH ₂ ... () (where R is previously explained in the general formula ()) The method of obtaining the compound of the general formula () by reacting the diamine represented by () is preferably employed. In the structural formulas represented by the above general formulas () and (), R ₁ , R ₂ and R ₃ in R are each selected from a hydrogen atom, a halogen atom, a nitro group, an alkyl group, an alkoxy group and a phenyl group. is an atom or group. The halogen atom is selected from chlorine, bromine, iodine, or fluorine as appropriate, and the alkyl group and alkyl group of the alkoxy group are not particularly limited, but are generally methyl, ethyl, propyl, and butyl groups. Lower alkyl groups having 1 to 5 carbon atoms are preferred. The raw material compound represented by the general formula () is
A compound represented by the general formula () obtained by reacting 3,4-dihydroxybenzaldehyde with tetraethylene glycol dichloride or pentaethylene glycol dichloride, or by reacting catechol with tetraethylene glycol dichloride or pentaethylene glycol dichloride (However, m is 3 or 4) It can be obtained by any known method in which an aldehyde group is introduced after obtaining the formula. There is no particular limitation on the reaction mode for obtaining the compound represented by the general formula () of the present invention from the reaction of 4'-formylbenzocrown ether represented by the general formula () with diamines, but in general, each reaction raw material is A method in which the aldehyde group and amino group are reacted in a solution or suspension state in an inert solvent is preferably employed. Examples of solvents suitably used in the above reaction include hexane,
Aliphatic hydrocarbons such as heptane and octane; Aromatic hydrocarbons such as benzene, toluene, and xylene; Aliphatic halogenated hydrocarbons such as methylene chloride, chloroform, and trichlorotrifluoroethane; Halogenated aromatic hydrocarbons; aliphatic alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, and diethylene glycol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; nitriles such as acetonitrile and benzonitrile; diethyl ether , diisopropyl ether, tetrahydrofuran, dioxane, and other ethers; methyl acetate, ethyl acetate, and other esters; formamide,
Examples include amides such as dimethylformamide and dimethylacetamide. The reaction temperature employed in reacting the formylbenzocrown ether with the diamine is not particularly limited, but it is generally sufficient to carry out the reaction between 50 and 150°C. Although the reaction time varies depending on the reaction temperature, reaction solvent, raw material concentration, etc., it is generally within the range of 10 minutes to 50 hours and may be appropriately determined and employed. In addition, when reacting formylbenzocrown ether with diamine, the reaction often proceeds without using a special catalyst, but boron trifluoride ethyl ether, p-toluenesulfonic acid,
Adding a small amount of acids such as sulfuric acid and phosphoric acid can significantly increase the reaction rate, which is industrially advantageous. Many of the compounds represented by the general formula () of the present invention obtained by the above reaction have high molecular weights and high boiling points, and therefore are difficult to distill. Therefore, it is usually preferable to purify by means such as extraction, recrystallization, column chromatography, etc. In particular, column chromatography is particularly suitable for most effectively separating the compound represented by the general formula () of the present invention from the raw materials 4'-formylbenzocrown ether and the diamine compound. When employing this method, it is desirable to determine the optimal conditions for the column packing material and developing solvent in advance by a technique such as thin layer chromatography. The compound represented by the general formula () of the present invention has a high selective coordination ability for potassium salts, and therefore can be used as a selective absorbent for potassium salts or as a component of a potassium-selective electrode. The mode of use as an extractant differs depending on the state of the potassium salt present. To give a specific representative example, when selectively extracting and removing potassium salt coexisting with sodium salt in an aqueous solution, the compound represented by the formula () of the present invention is dissolved in an organic solvent that is immiscible with water. By bringing the organic solvent into contact with the aqueous phase, the potassium salt can be selectively extracted into the organic solvent from the aqueous phase. There are no particular limitations on the mode of constructing a potassium selective electrode using the compound represented by the general formula () of the present invention as one component.
Electrodes in Analytical Chemistry (Plenum
Press1978) Chapters 3 and 4, Analytical
Various known methods can be used, such as those described in Chemistry 47 , 2238 (1975). To give a specific example, a compound represented by the general formula () of the present invention is dissolved in a water-insoluble organic compound such as nitrobenzene, bromobenzene, diphenyl ether, etc., and a glass capillary, a ceramic porous membrane, a porous polymer membrane, etc. A method for retaining it in a film is to use an appropriate method such as silicone rubber, polyvinyl chloride containing a plasticizer, polymethyl methacrylate containing a plasticizer, etc., for example, by dissolving it in a common solvent and then evaporating the solvent to once form a film-like material. A potassium selective electrode can be constructed by attaching this film-like material to an electrode cell, or by forming a thin film directly on a silver wire, a platinum wire, or a gate portion of a silicon semiconductor device. The plasticity used here is not particularly limited and any known plasticity may be used. For example, phthalate esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, and dioctyl phthalate; fatty acid esters such as dioctyl adipate and dioctyl sebacate; phosphoric acid esters such as tricresyl phosphate; orthonitrophenyl octyl ether Examples include orthonitrophenyl alkyl ethers such as. A specific example of an electrode using the compound of the present invention as an electrode film is shown in FIGS. 7 and 8. That is, FIG. 7 is an explanatory diagram of an apparatus for measuring electromotive force, and FIG. 8 is an explanatory diagram showing various constituent elements built into the electrode of FIG. 7. The membrane prepared from the compound of the present invention is installed in membrane 16 in FIG. 8 and used as a component of a potassium selective electrode. In addition, in Figures 7 and 8,
Each numerical value indicates the following. 1 Electrode 2 Measurement solution 3 Magnetic rotor 4 Magnetic stirrer 5 Lithium acetate salt bridge 6 Saturated aqueous potassium chloride solution 7 Saturated electrode 8 Electrometer 11 Acrylic membrane holder 12 Silver wire 13 Covered glass tube 14 Silver monochloride wire 15 Potassium chloride Internal standard solution 16 Membrane 17 O-ring Examples will be given below to explain the present invention more specifically, but the present invention is not limited to these Examples. Example 1 Distilled O-phenylenediamine was placed in an eggplant-shaped flask with an internal volume of 100 ml equipped with a cooling tube and a water metering receiver.
0.37g (3.4 mmol) and 2.0 g (6.8 mmol) of the compound represented by (hereinafter simply abbreviated as 4'-formylbenzo 15 crown 5) and one drop of boron trifluoride ethyl ether as a catalyst were added to the oil while stirring with a magnetic rotor. It was heated in a bath and subjected to azeotropic dehydration for 10 hours. During this time, 0.1 ml of water was distilled out. After the reaction, benzene was distilled off, and the product was transferred to a column filled with silica gel (product name: WAKO-Gel-200) in a mixed solvent of ethyl acetate/acetone/water (volume ratio).
70/20/4) was used as a developing solvent to obtain 830 mg of a yellowish brown liquid. Yield 38%. The following analysis was performed on the obtained product. (1) Infrared absorption spectrum (results are attached as Figure 1) -CH=N- 1640cm ^-1 aromatic ring 1000cm ^-1 cyclic ether 1270cm ^-1 , 1130cm ^-1 (2) ¹ H - nuclear magnetic resonance spectrum ( Results are attached as Figure 2) Measurement solvent: Deuterated chloroform Standard material: Tetramethylsilane (a) 8.2-8.3δ (ppm) (b) 6.5-7.4δ (ppm) (c) 3.5-4.3δ (ppm) (3) Mass spectrometry spectrum FD method: m/e=664 (M ⁺ ) (4 ) elemental analysis

[Table] From the above measurement results, it was confirmed that the product was the desired product. Examples 2 to 19 2.0 g (6.8 mmol) of 4'-formylbenzo 15 crown 5 was added to a 100 ml eggplant-shaped flask equipped with a cooling tube and a water metering receiver, and the general formula H ₂ N-R-
3.7 mmol of diamine represented by NH ₂ and 50 ml of benzene were charged, one drop of boron trifluoride ethyl ether was added as a catalyst, and the mixture was heated in an oil bath while stirring with a magnetic rotor, and azeotropically dehydrated for 10 hours. After the reaction, benzene was distilled off and the product was purified in the same manner as in Example 1. The yield and properties of the reactants are summarized in Table 1.

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[Table] The substances obtained in Examples 2 to 29 were analyzed in the same manner as in Example 1, and it was confirmed that they were the desired substances. For reference, the infrared absorption spectrum and ¹ H-nuclear magnetic resonance spectrum of Example 12 are shown in FIGS. 3 and 4, respectively. Examples 30-48 In an eggplant-shaped flask with an internal volume of 100 ml equipped with a cooling tube and a water metering receiver. 2 g (5.8 mmol) of the compound represented by (hereinafter abbreviated as 4'-formylbenzo 18 crown 6) and
2.9 mmol of diamine represented by _H2N -R- _NH2 was added, and a reaction was carried out in the same manner as in Example 1. Table 2 shows the yield and properties of the reactants.

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[Table] The above-obtained substances were analyzed in the same manner as in Example 1, and each was confirmed to be the desired substance. For reference, the infrared spectrum of Example 30 and
¹ H-nuclear magnetic resonance spectra are shown in Figure 5 and
It is shown in Figure 6. Example 59 Using the compounds of the present invention obtained in Examples 1 to 58 above, according to the method described in Chapter 1, Section 1 of "Chemistry of Crown Ethers and Cryptands" (Kagaku Dojin, 1979), The compounds of the invention were used to extract potassium and sodium picrate from the aqueous phase into the organic phase. Mix 5 ml of a methylene chloride solution containing the compound of the present invention at a concentration of 3 x 10 ^-4 M with 5 ml of an aqueous solution containing potassium hydroxide or sodium hydroxide at a concentration of 10 ^-2 M and picric acid at a concentration of 7 x 10 ^-5 M. After shaking vigorously for 5 minutes at 23°C, the mixture was allowed to stand to separate the aqueous and organic phases. The extraction rate of potassium picrate or sodium picrate extracted into the organic phase was determined by absorption at 374 nm using a visible absorption spectrum. The results are shown in Table 3.

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[Table] For comparison, a similar experiment was conducted using 4'-formylbenzo 15 crown 5, and the results showed that the extraction rate of potassium picrate was 17.7%, the extraction rate of sodium picrate was 5.1%, and the extraction rate of potassium picrate/ The sodium picrate extraction rate ratio was 3.5. Application Example An application example of the compound of the present invention to a potassium selective electrode will be shown. 10 mg of the compound of the present invention obtained in Examples 1 to 58, 200 mg of polyvinyl chloride (degree of polymerization 1300),
Orthonitrophenyl octyl ether 400mg
Dissolved in 10ml of tetrahydrofuran. After casting this solution onto a smooth glass plate, the tetrahydrofuran was evaporated to obtain a film approximately 100 microns thick. This membrane was mounted as shown in FIGS. 7 and 8, and the electrode performance was evaluated using the apparatus shown in FIGS. 7 and 8. All measurements were performed at 25°C. The selection ratio of potassium ions to sodium ions can be determined using the "ion selective electrode" (Kyoritsu Shuppan)
(1977) was determined by the mixed solution method described in Chapter 2, Section 3. Specifically, in an aqueous solution containing potassium chloride and sodium chloride, the electromotive force was measured while keeping the concentration of potassium chloride constant (10 ^-4 M) and varying the concentration of sodium chloride. Then, the relationship between the electromotive force and the sodium chloride concentration was plotted, and the value obtained by dividing the concentration of sodium chloride at the inflection point by the concentration of potassium chloride was used as the selection magnification. The larger this value is, the more excellent the electrode is as a selective electrode. In addition, we measured the electromotive force of an aqueous solution containing only potassium chloride in the concentration range of 10 ^-1 to ^{10 -5} M, and from the relationship between the electromotive force and the potassium chloride concentration, we calculated the slope for a 10-fold change in the potassium chloride concentration. The amount of change in electromotive force was determined in mV/decade. The results are shown in Table 4.

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【table】 [Brief explanation of the drawing]

FIGS. 1 and 2 are an infrared absorption spectrum and a ¹ H-nuclear magnetic resonance spectrum of the compound obtained in Example 1, respectively. Figures 3 and 4 show the infrared absorption spectrum and the infrared absorption spectrum of the compound obtained in Example 12, respectively.
^1H -nuclear magnetic resonance spectrum. FIGS. 5 and 6 are the infrared absorption spectrum and ¹ H-nuclear magnetic resonance spectrum of the compound obtained in Example 30, respectively. Figure 7 is an explanatory diagram of a device that measures electromotive force.
FIG. 8 is an explanatory diagram showing various constituent elements built into the electrode 1 of FIG. 7. The numerical values in FIGS. 7 and 8 indicate the following contents. DESCRIPTION OF SYMBOLS 1... Electrode, 2... Measurement solution, 3... Magnetic rotor, 4... Magnetic stirrer, 5... Lithium acetate salt bridge, 6... Potassium chloride saturated aqueous solution, 7... Saturated electrode, 8... Electrometer, 11
... Acrylic film holder, 12 ... Silver wire, 13
...Coated glass tube, 14 ... Silver monochloride wire, 15
...10 ^-3 M potassium chloride internal standard solution, 16 ... film-like substance, 17 ... O-ring.

Claims (1)

[Claims] 1 General formula, [However, m is 3 or 4, and R is [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] (where R ₁ , R ₂ , and R ₃ are hydrogen atoms, halogen atoms,
A Schiff base-type biscrown ether, which is a different or similar atom or group selected from a nitro group, an alkyl group, an alkoxy group, and a phenyl group.