Process for producing 5-bromo-2-adamantanone
The method of brominating 2-adamantanone with bromine, aluminum halide, and unsaturated aliphatic compounds addresses the cost and yield issues of existing methods, enabling the efficient and cost-effective production of 5-bromo-2-adamantanone.
Patent Information
- Application Number
- JP2021165139
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-10-07
- Publication Date
- 2025-06-26
- Estimated Expiration
- 2041-10-07
AI Technical Summary
Existing methods for producing 5-bromo-2-adamantanone are costly, require expensive reagents, and have low yields or require high temperatures, making them industrially impractical.
A method involving the bromination of 2-adamantanone using bromine in the presence of aluminum halide and/or metallic aluminum and various unsaturated aliphatic compounds, which simplifies and economizes the production process.
This method allows for the economical and simple production of 5-bromo-2-adamantanone with high yields, using inexpensive reagents and at moderate temperatures, making it industrially advantageous.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a novel method for producing 5-bromo-2-adamantanone. Adamantane derivatives are expanding their applications in various industrial fields due to their properties such as high heat resistance and transparency. For example, they are known to be useful as electronic materials such as photoresists for semiconductor manufacturing, functional materials, and raw materials for medical and agricultural chemicals.
Background Art
[0002] As a method for producing 5-bromo-2-adamantanone, for example, a method of brominating 2-adamantanone using bromine in the presence of aluminum bromide and tert-butyl bromide has been proposed (see, for example, Non-Patent Document 1). However, this production method requires expensive aluminum bromide and tert-butyl bromide and takes two days for the reaction, so it is difficult to say that it is an industrially advantageous method.
[0003] In addition, a method of brominating with carbon tetrabromide using a quaternary ammonium salt as a phase transfer catalyst (see, for example, Non-Patent Document 2) and a method of brominating with carbon tetrabromide using an iron catalyst (see, for example, Non-Patent Document 3) have been proposed. However, in both Non-Patent Document 2 and Non-Patent Document 3, harmful carbon tetrabromide is used as a brominating agent. Further, in the production method described in Non-Patent Document 2, the yield of 5-bromo-2-adamantanone is as low as 31%, and in the production method described in Non-Patent Document 3, there is also a problem that a reaction at a high temperature of 170 °C is required.
Prior Art Documents
Non-Patent Documents
[0004]
Non-Patent Document 1
Non-Patent Document 2
Non - Patent Document 3
Summary of the Invention
Problems to be Solved by the Invention
[0005] In view of these prior arts, an object of the present invention is to provide a method for economically and simply producing 5 - bromo - 2 - adamantanone.
Means for Solving the Problems
[0006] As a result of intensive studies on an inexpensive and simple production method of 5 - bromo - 2 - adamantanone, the present inventors have found that 2 - adamantanone can be easily brominated using bromine in the presence of aluminum halide and / or metallic aluminum and various unsaturated aliphatic compounds to produce 5 - bromo - 2 - adamantanone, thus completing the present invention.
[0007] That is, the present invention relates to the following. [1] A method for producing 5 - bromo - 2 - adamantanone, characterized by reacting 2 - adamantanone with bromine in the presence of aluminum halide and / or metallic aluminum and an unsaturated aliphatic compound. [2] The production method according to item [1], characterized in that the unsaturated aliphatic compound is at least one selected from the group consisting of linear, branched, or cyclic unsaturated aliphatic compounds having 2 to 8 carbon atoms.
Effects of the Invention
[0008] According to the production method of the present invention, 5 - bromo - 2 - adamantanone can be produced economically and simply using inexpensive aluminum halide and / or metallic aluminum and various unsaturated aliphatic compounds.
Modes for Carrying Out the Invention
[0009] The present invention will be described in detail below.
[0010] The present invention relates to a method for producing 5-bromo-2-adamantanone, which is characterized by reacting aluminum halide and / or metallic aluminum with 2-adamantanone in the presence of an unsaturated aliphatic compound and bromine.
[0011] Examples of the aluminum halide that can be used in the method of the present invention include aluminum chloride, aluminum bromide, and aluminum iodide. Here, regarding the amount of aluminum chloride or metallic aluminum used, or the case where both are used in combination, in the method of the present invention, there is no particular limitation. Usually, it is used in the range of 0.5 to 10 times the molar amount with respect to 1 mol of 2-adamantanone. Considering the reactivity and the complexity in the post-treatment process, it is preferably in the range of 1.0 to 5 times the molar amount. In the method of the present invention, when metallic aluminum is used, aluminum in a generally known shape that is usually used can be used as it is. Specifically, forms such as powder, granular, flake, chip, and lump can be mentioned.
[0012] The unsaturated aliphatic compound used in the method of the present invention is preferably at least one selected from the group consisting of linear, branched, or cyclic unsaturated aliphatic compounds having 2 to 8 carbon atoms. That is, it is a linear, branched, or cyclic aliphatic compound having 2 to 8 carbon atoms and containing an unsaturated bond between carbon-carbon atoms in the molecule. Specific examples thereof include compounds containing a double bond between carbon-carbon atoms in the molecule, such as ethylene, propylene, 1-butene, 2-butene, isobutene, 1-pentene, 2-pentene, 3-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene, 1-hexene, 2-hexene, 3-hexene, 2-methyl-1-pentene, 2-methyl-2-pentene, 1-heptene, 2-heptene, 3-heptene, 4-heptene, 2-methyl-1-hexene, 2-methyl-2-hexene, 1-octene, 2-octene, 3-octene, 4-octene, 2-methyl-1-heptene, 2-methyl-2-heptene, etc.; compounds containing a cyclic structure in the molecule, such as cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, etc.; compounds containing a triple bond between carbon-carbon atoms in the molecule, such as acetylene, propyne, 1-butyne, 2-butyne, 1-pentyne, 2-pentyne, 1-hexyne, 2-hexyne, 3-hexyne, 1-heptyne, 2-heptyne, 3-heptyne, 1-octyne, 2-octyne, 3-octyne, 4-octyne, etc. These can be used alone or as a mixture of any arbitrary combination thereof.
[0013] In the method of the present invention, there is no particular limitation on the amount of the unsaturated aliphatic compound used, but it is used in the range of 0.1 to 10 times the molar amount with respect to 1 mol of 2-adamantanone, and preferably in the range of 0.5 to 3.0 times the molar amount in consideration of reactivity and economy.
[0014] In the method of the present invention, there is no particular limitation on the amount of bromine used, but it is used in the range of 1.0 to 50 times the molar amount with respect to 1 mol of 2-adamantanone, and preferably in the range of 3.0 to 20 times the molar amount in consideration of reactivity and the complexity in the post-treatment process. In the method of the present invention, bromine used as a brominating agent may be used as a solvent, but if necessary, halogenated hydrocarbon solvents such as dichloromethane, dibromomethane, dichloroethane, dibromoethane, etc. may be used. When using a halogenated hydrocarbon solvent, 1 to 20 parts by weight is used with respect to 1 part by weight of 2-adamantanone.
[0015] Regarding the reaction temperature in the method of the present invention, it is in the range of 20°C to 65°C, preferably in the range of 40°C to 60°C. The reaction time varies depending on the aliphatic halide used, but usually, the reaction is completed by carrying out the reaction for 10 hours to 72 hours.
[0016] After the reaction is completed, the active substance is deactivated according to a conventional method, and then the product is extracted. Subsequently, the organic layer is washed with water, the solvent is distilled off, and then the target 5-bromo-2-adamantanone is obtained by ordinary purification operations such as recrystallization.
Examples
[0017] Examples of the present invention are shown below, but the present invention should not be construed as being limited to these examples.
[0018] Note that the yield is a value determined by gas chromatography (GC) under the following conditions. <Measurement by Gas Chromatography (GC)> · Apparatus: GC7820A (manufactured by Agilent Technologies, Inc.) · Column: Capillary column TC-1 (manufactured by GL Sciences Inc.) · Internal standard: Cyclododecane Measurement and quantification were carried out by the internal standard method using cyclododecane in accordance with the operating method of the GC apparatus.
[0019] Also, the conditions for nuclear magnetic resonance and mass spectrometry are as follows. <Measurement by Nuclear Magnetic Resonance> · Apparatus: Avance 400 (manufactured by Bruker Corporation) · Solvent: Deuterated chloroform <Measurement by Mass Spectrometry (GCMS)> · Apparatus: GCMS-QP2010Plus (manufactured by Shimadzu Corporation) · Column: Capillary column TC-1 (manufactured by GL Sciences Inc.)
[0020] Example 1 Preparation of 5-Bromo-2-adamantanone To a 100 mL eggplant-shaped flask equipped with a stir bar, 2-adamantanone (1.0 g, 6.66 mmol), aluminum chloride (1.78 g, 13.3 mmol), and bromine (21.3 g, 133 mmol) were added. The mixture was cooled to 0 °C with stirring, and 1-pentene (0.47 g, 6.66 mmol) was added dropwise at the same temperature. After the addition, the temperature was raised to 50 °C and aged for 24 hours. After completion of the reaction, water (5 mL) was added to the reaction solution to deactivate aluminum chloride, and then a saturated aqueous solution of sodium sulfite (50 mL) was added to reduce bromine. Thereafter, dichloromethane (20 mL) was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous solution of sodium hydrogen carbonate (10 mL), and then the solvent was distilled off under reduced pressure. The compound obtained as described above was analyzed by nuclear magnetic resonance and mass spectrometry. As a result, it was confirmed that the compound was 5-bromo-2-adamantanone. The yield quantified by gas chromatography was 93.8%.
[0021] Examples 2 to 10 Preparation of 5-Bromo-2-adamantanone Using the same reaction apparatus as in Example 1, under the conditions shown in Table 1, the unsaturated aliphatic compound and its molar ratio were variously changed, and the same reaction was carried out. The obtained results are shown in Table 1.
[0022] Comparative Example 1 Case of Not Using Unsaturated Aliphatic Compound Using the same reaction apparatus as in Example 1, the procedure was carried out in the same manner as in Example 1 except that 1-pentene was not used. When the compound obtained as described above was analyzed by gas chromatography, it was almost unreacted and the yield was less than 0.1%. This result is shown in Table 1 together with other examples.
[0023] Comparative Example 2 Case of Not Using Unsaturated Aliphatic Compound Using the same reaction apparatus as in Example 1, the procedure was carried out in the same manner as in Example 1 except that 1-pentene was not used and aluminum bromide was used instead of aluminum chloride. The obtained results are shown in Table 1.
[0024] Reference Example 1 Using the same reactor as in Example 1, the reaction shown in the following reaction formula described in the following Non-Patent Document 1 was carried out. Specifically, tert-butyl bromide (t-BuBr) was added dropwise to a reactor containing 2-adamantanone and aluminum bromide, and the reaction was carried out. It took 48 hours until the reaction was completed. The results obtained are shown in Table 1. Synthetic Communications, 1979, Vol. 9, pp. 825-830 (Non-Patent Document 1).
Chemical formula
Table 1
[0025] According to Table 1, the following can be understood. Looking at the results of Examples 1 to 4, it seems that the reaction rate varies according to the amount of the unsaturated aliphatic compound with respect to the amounts of bromine and Al species in the reaction. That is, in Example 2 with a short reaction time, the amount of 1-pentene is large, followed by Example 3, Example 1, and Example 4 in that order. This seems to indicate that the rate-determining step of the reaction is due to the unsaturated aliphatic compound in the bromination reaction, and shows that the presence of the unsaturated aliphatic compound in the present invention acts suitably for an efficient reaction.
[0026] Regarding the various unsaturated aliphatic compounds used in Examples 1 to 10, good results can be obtained in both the reaction rate and the yield, and no significant difference was observed among the types of unsaturated aliphatic compounds tested for the suitable compounds.
[0027] When Example 2 is compared with Example 7, in Example 2, AlCl3 is used as the Al species, and in Example 7, Al powder is used as the Al species. Although no significant difference was observed in the reaction yields, the reaction time was 8 hours in Example 2 and 36 hours in Example 7. It is considered that AlCl3 acts more easily in terms of the form related to the reaction.
[0028] When Example 2 is compared with Comparative Example 1, in both cases, AlCl3 is used as the Al species, and the reaction conditions are generally the same except that an unsaturated aliphatic compound is not used in Comparative Example 1. Also, when Example 3 is compared with Comparative Example 2, in both cases, AlBr3 is used as the Al species, and the reaction conditions are generally the same except that an unsaturated aliphatic compound is not used in Comparative Example 2. As a result, in Comparative Example 1 and Comparative Example 2, the reaction yield is less than 0.1%, and substantially no target product is formed. From this, it can be seen that the presence of the unsaturated aliphatic compound is essential for the formation of the target product. Here, in Reference Example 1, similar to Example 3 and Comparative Example 2, AlBr3 is used as the Al species. The difference is that t-BuBr is used instead of the unsaturated aliphatic compound. In Reference Example 1, as shown in Table 1, although the reaction yield is relatively high at 97.9%, the reaction time is extremely long at 48 hours and requires a very long reaction time. Furthermore, although not described in Table 1, in the table on page 827 of Non-Patent Document 1, it requires a reaction for a long period of time that is not practical, ranging from 3 days (72 hours) to 10 days (240 hours). Therefore, just by looking at the results of Example 2, it can be seen that the present invention is a method for producing practical 5-bromo-2-adamantanone.
Industrial Applicability
[0029] By the method of the present invention, industrial and inexpensive 5-bromo-2-adamantanone can be produced, which is very useful industrially as a raw material for electronic materials, functional materials, and intermediates for medical and agricultural chemicals, etc.
Claims
1. A method for producing 5-bromo-2-adamantanone, which comprises reacting aluminum halide and / or metallic aluminum with 2-adamantanone and bromine in the presence of an unsaturated aliphatic compound.
2. The production method according to claim 1, wherein the unsaturated aliphatic compound is at least one selected from the group consisting of linear, branched, or cyclic unsaturated aliphatic compounds having 2 to 8 carbon atoms.