TW201509894A - Oxidation method of alcohol - Google Patents

Abstract

The oxidation reaction of alcohol converted into carbonyl compounds is considered one of the important reactions in organic synthesis. PROBLEM TO BE SOLVED: To provide an alcohol oxidation method of high productivity and safe convenience that is able to obtain a desired product with high yield and selectivity. SOLUTION: An alcohol oxidation method is used to oxidize an alcohol, which is represented by the following general formula (1) (wherein, R1 represents an alkyl group, an aryl group or an aralkyl group, R2 represents an alkyl group, an aryl group, an aralkyl group or a hydrogen atom), to produce carbonyl compounds derived by the foregoing alcohol. The oxidation method of alcohol is characterized in that sodium hypochlorite pentahydrate (NaOCl.5-H2O) is used, in the presence or absence of catalyst, as an oxidizing agent.

Description

Alcohol oxidation method

The present invention relates to an oxidation method of an alcohol, and particularly relates to an alcohol which is used for oxidizing an alcohol to produce a carbonyl compound such as an aldehyde, a carboxylic acid or a ketone derived from the aforementioned alcohol, using sodium hypochlorite 5 hydrate as an oxidizing agent. The oxidation method of the class.

There have been many reports of methods for oxidizing alcohols to produce carbonyl compounds such as aldehydes, carboxylic acids or ketones, but the oxidizing agents, catalysts and their wastes used are harmful, or explosive and oxidized. Since the reaction requires low-temperature conditions and the like, and there are various restrictions on the oxidizing agent to be used, it has been desired in many fields to develop an oxidation method of an alcohol which can safely and easily produce a carbonyl compound of a target product with good yield and good selectivity.

One of the methods that meet this type of requirement has been proposed to use sodium hypochlorite as an oxidation method for alcohols used in oxidants, and many research cases have been reported.

For example, Non-Patent Document 1 reports that sodium hypochlorite aqueous solution (pH 12-13) is used as an oxidizing agent, and TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy; 2,2,6,6 -tetramethyl-1-piperidinyloxy) is used as a catalyst, and NaHCO _{3 is} used as a buffer for adjusting the reaction system to pH 8 to 9, and if necessary, KBr is used as a catalyst, and the reaction temperature is around 0 ° C. The first or second alcohols are oxidized to the corresponding aldehydes or ketones. In Non-Patent Document 1, it is known from comparative experiments that the reaction of pH 12 to 13 at an unadjusted pH greatly reduces the yield of the desired product, and it has been reported that the safety of the next aqueous sodium chlorate solution by TEMPO and KBr coexisting. According to the test data, the sodium chlorate will decompose rapidly at room temperature.

Further, in the above-described oxidation method of using an aqueous solution of sodium hypochlorite as an oxidizing agent in combination with a nitroxide radical compound represented by TEMPO as a catalyst, the oxidation reaction is further improved in reaction rate and substrate selectivity. For the purpose of reaction temperature, waste liquid treatment, environmental harmonization, etc., AZADO (2-aza-adamantane N-hydroxyl; 2-azaadamantane) is used for the chemical structure of a nitroxide-based radical compound used as a catalyst. N-oxyl) is a catalyst (refer to Non-Patent Document 2, Patent Documents 1 and 2), or a pH is maintained at about 4.0 to 8.0 by a phosphate buffer solution, and a method of using sodium hypochlorite and sodium chlorite solution (refer to a patent) Document 3), or a method in which a helper catalyst is changed to KBr, and an oxymetal ion such as Na ₂ B ₄ O ₇ or ZrO (acetate) ₂ or a salt thereof (refer to Patent Document 4) is used, and TEMPO is used. The catalyst system works.

Prior technical literature Patent literature

[Patent Document 1] Japanese Patent No. 04,809,229

[Patent Document 2] Japanese Patent No. 04,803,074

[Patent Document 3] Japanese Patent Publication No. 2002-511,440

[Patent Document 4] Japanese Patent Publication No. 2006-517, 584

[Non-Patent Document 1] P. L. Anelli, et al., J. Org. Chem. 1987, 52, 2559-2562

[Non-Patent Document 2] Y, Iwabuchi et al., J. Am. Chem. Soc., 2006, 128, 8412-8413

Summary of invention

However, sodium hypochlorite used as an oxidizing agent is generally distributed in an aqueous solution (pH 12 to 13) of about 12% by mass. The aqueous sodium hypochlorite solution is an alcohol having a large amount of water and a nitrate-based radical compound as a catalyst. In the oxidation reaction, when a sodium hypochlorite aqueous solution having a pH of 12 to 13 is used as it is, a high yield cannot be obtained. Therefore, a buffer such as NaHCO _{3 for} adjusting the pH of the reaction system is indispensable, but in order to use the buffer, a large amount of water is required. As a result, there is a very large amount of water in the reaction system.

For example, in the experimental item of Non-Patent Document 2 [Ref. 8413, References (9)], when 200 mg of 3-phenylpropanol is oxidized, 3.9 mL of dichloromethane for working solvent and NaHCO ₃ aqueous solution for pH adjustment are used. 2mL, and an oxidizing agent sodium hypochlorite aqueous solution (8 mass% concentration) and a mixture of NaHCO ₃ aqueous solution 3.3mL, so the total amount of organic solvent and aqueous solution is 9.2mL with respect to 200mg of the substrate (alcohol), but the calculation is simple When the oxidation substrate is 1 kg, the reaction system has not only 26.5 L of the aqueous solution alone, but if it contains an organic solvent, it becomes necessary to have a solution of up to 46 L, resulting in a very thin reaction condition.

Therefore, the reaction system is an extremely lean condition, and the oxidation reaction of the alcohol at the laboratory level is not problematic, but the alcohol (the matrix) is placed in the reactor when the oxidation reaction of the alcohol is carried out at an industrial level requiring mass production. The amount is limited, and the production of carbonyl compounds which can be obtained by one oxidation reaction in one reactor is also limited, so the production efficiency is extremely lowered, and a large amount of waste liquid which is generated also needs to be huge. Processing costs, so there are problems of high production costs and lack of practicality. Further, when the oxidation reaction is carried out by using an aqueous solution of sodium hypochlorite without adjusting the pH alone, the phase shifting catalyst is often used in a low yield, which is not suitable for industrial production.

Therefore, the inventors of the present invention can increase the ratio of the reaction system to the matrix of the oxidizing agent (hereinafter referred to as "the ratio of the matrix relative to the oxidizing agent") in the oxidation reaction of the alcohol, without lowering the reaction efficiency or the environmental compatibility. A method of solving the problems of production efficiency and waste disposal has been focused on the high-purity crystallization of sodium hypochlorite 5 hydrate (NaOCl.5H ₂ O) with a general effective chlorine concentration of about 42% by mass and a sodium hydroxide concentration of 0.1% by mass or less. When it is used as an oxidizing agent, it is not necessary to adjust the pH of the reaction system, and as a result, the moisture content of the reaction system can be reduced as much as possible, and the oxidation method of the alcohol which previously used the nitrate-based radical compound as a catalyst can be compared, and the overwhelming property can be improved relative to The ratio of the matrix of the oxidizing agent is subjected to an oxidation reaction to complete the present invention.

Accordingly, an object of the present invention is to provide a novel oxidation method of an alcohol which can improve the production efficiency with respect to the ratio of the matrix of the oxidant in the oxidation reaction of the alcohol.

That is, the present invention is a feature system, and the following general formula (1) (Formula, R ¹ represents an alkyl group, an aryl group or an aralkyl group, and R ² represents an alkyl group, an aryl group, an arylalkyl group or a hydrogen atom) is oxidized by an alcohol to produce the following general formula (2) In the method of oxidizing an alcohol of the carbonyl compound represented by the formula (wherein R ¹ is an alkyl group, an aryl group or an aralkyl group, and R ³ is an alkyl group, an aryl group, an aralkyl group, a hydrogen atom or a hydroxyl group), sodium hypochlorite is used. A method of oxidizing an alcohol of 5 hydrate as an oxidizing agent.

The method for oxidizing an alcohol of the present invention as an alcohol for a substrate The alcohol represented by the above general formula (1) is not required to use a catalyst such as TEMPO or AZADO because sodium chlorate 5 hydrate used as an oxidizing agent in the reaction system is free, and thus the nitroxide used as the catalyst is free. The base compound (nitridyl radical catalyst) has no problem of steric hindrance, but may be a second-order alcohol having a large steric hindrance.

Further, in the oxidation method of the present invention, the sodium hypochlorite 5 hydrate (NaOCl.5H ₂ O) used as the oxidizing agent is not particularly limited as long as it is a commercially available product, and the effective chlorine concentration is 39% by mass or more, preferably about 42% by mass. %, and the sodium hydroxide concentration (NaOH concentration) is preferably 0.2% by mass or less, preferably 0.1% by mass or less. When the effective chlorine concentration is less than 39% by mass, it is likely to be liquidified by the liquidification to promote the decomposition of sodium hypochlorite during storage, and when the NaOH concentration is higher than 0.2% by mass, a buffer for adjusting the pH is used, which may reduce the total amount of the reaction mixture. The ratio of the matrix (hereinafter referred to as "the ratio of the matrix of the reaction system"). Such sodium hypochlorite 5 hydrate (NaOCl.5H ₂ O) can be produced, for example, by the method described in Japanese Patent No. 04,211,130.

In the present invention, when sodium hypochlorite 5 hydrate is used as an oxidizing agent in a reaction system for oxidizing an alcohol, sodium hypochlorite 5 hydrate can be dissolved in water and used, but considering the reaction rate and the ratio of the matrix of the reaction system, generally, effective chlorine is used. The aqueous solution or the powdery crystal having a concentration of 12% by mass or more is preferably an aqueous solution or a powdery crystal having an effective chlorine concentration of 20% by mass or more, more preferably an aqueous solution or a powdery crystal having an effective chlorine concentration of 30% by mass or more. The sodium hypochlorite 5 hydrate used as an oxidizing agent generally has a NaOH concentration of 0.1% by mass or less, and thus can be highly concentrated. Crystallization can be used directly. For example, sodium hypochlorite 5 hydrate having an effective chlorine concentration of about 42% by mass is about 3.5 times higher than an aqueous solution of sodium hypochlorite having an effective chlorine concentration of about 12% by mass, so that in addition to increasing the ratio of the matrix relative to the oxidizing agent by about 3.5 times, It also has the advantage of increasing the reaction rate at high concentrations. When sodium hypochlorite 5 hydrate having an effective chlorine concentration of less than 12% by mass is used, it is not necessary to use water used for the buffer for pH adjustment, so that the oxidation reaction using the nitroxide-based radical catalyst can be compared with the previous one. Increasing the proportion of the matrix of the reaction system, but only lowering the effective chlorine concentration will reduce the ratio of the matrix relative to the oxidant.

Further, in the oxidation method of the present invention, when sodium hypochlorite 5 hydrate is used as the oxidizing agent, the reaction can be carried out without using a nitroxide-based radical catalyst and/or a phase-shifting catalyst in combination, but if necessary, nitroxide-based radicals can be used in combination. The catalyst and/or the interphase moving catalyst can shorten the reaction time by using the nitroxide-based radical catalyst and/or the same mobile catalyst in combination with the type of the alcohol suitable for the oxidation method of the present invention. The reaction yield can be improved.

The nitroxide-based radical catalysts used in this category are, for example, various nitroxide-based radical compounds previously known, for example, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), 4 TEMPO-catalysts such as hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy, 4-methoxy-2,2,6,6-tetramethyl-1-piperidinyloxy , aza-adamantyl-N-hydrocarbyloxy compound (AZADO)-based catalyst, and azabicyclo[3,3,1]nonane-N-hydrocarbyloxy compound, etc. A mixture of two or more kinds may be used alone or in combination. When the nitroxide-based radical catalyst is used in combination, the amount of the catalyst used may be, and the amount of the catalyst used is generally 0.00001 equivalent or more and 0.1 equivalent or less. It is preferably in the range of 0.001 equivalent or more and 0.01 or less.

Further, the aforementioned interphase moving catalyst is, for example, various phase-shifting catalysts previously known, for example, a 4-grade ammonium salt, a 4-grade phosphonium salt, a polyethylene glycol, a crown ether, an alkyl sulfate, and Alkyl sulfonate, amphoteric surfactant, etc., representative of, for example, tetrabutylammonium hydrogen sulfate, tetrabutylammonium bromide, tetrabutylammonium chloride, Aliguat 336, trioctylmethylammonium hydrogen sulfate, 18 - Crown-6, tetrabutylphosphonium chloride, sodium lauryl sulfate, lauryl dimethylaminoacetic acid betaine, etc., and these may be used alone or in combination of two or more. The amount of use of the phase-shifting catalyst may be a so-called amount of the catalyst, and is generally 0.001 equivalent or more and 0.1 equivalent or less, preferably 0.01 equivalent or more and 0.05 equivalent or less, based on the total amount of the alcohol.

In the oxidation method of the present invention, the oxidation reaction may be carried out in a solvent in which an organic solvent of an alcohol for a matrix is dissolved, or may be carried out in a solvent-free manner without using an organic solvent. The organic solvent to be used in the solvent is a solvent which is not oxidized by the oxidizing agent sodium hypochlorite 5 hydrate, for example, a halogen solvent such as dichloromethane, chloroform or dichloroethane, or ethyl acetate or acetic acid. An ester-based solvent such as butyl ester or an electron-deficient aromatic solvent such as nitrobenzene, benzotrifluoride or 4-chlorobenzotrifluoride is preferably a halogen solvent or an ester solvent. When the oxidation method of the present invention is carried out in a solvent using an organic solvent, the organic solvent and the aqueous solution or crystal (solid) of sodium hypochlorite as an oxidizing agent form a reaction of a heterogeneous system, and therefore it is preferred to use the above-mentioned phase shift catalyst.

Moreover, in the oxidation method of the present invention, the oxidation reaction can be single It is carried out under the agitation only by bringing the alcohol into contact with the oxidizing agent sodium hypochlorite 5 hydrate. Secondly, although the reaction time is longer than the previous method using the nitroxide radical catalyst, it is carried out even at room temperature, and When the mixture is stirred at a temperature below room temperature for 1 day, an aldehyde-derived carbonyl compound such as an aldehyde or a ketone can be obtained in a high yield. Therefore, the oxidation reaction of the present invention is generally carried out by stirring at a reaction temperature of from 0 ° C to 50 ° C, preferably at a reaction temperature of from 0 ° C to room temperature (about 30 ° C). When the reaction temperature is above room temperature, the decomposition reaction and oxidation reaction of sodium hypochlorite will become a competitive reaction, but it is not appropriate to increase the amount of sodium hypochlorite 5 hydrate when sodium hypochlorite is decomposed, and the reaction temperature is lowered until the reaction system does not solidify. When the degree of low temperature (less than 0 ° C), in addition to the need for the corresponding equipment, it will lead to a decrease in the reaction speed, etc., but the advantages are less.

In the oxidation method of the present invention, it is not necessary to adjust the pH of the reaction system when the oxidation reaction is performed, so that the buffer for adjusting the pH and the water for the purpose can be omitted, and the ratio of the matrix of the reaction system can be increased to substantially increase the production. effectiveness.

According to the oxidation method of the alcohol of the present invention, in addition to the ratio of the matrix to the oxidizing agent in the oxidation reaction of the alcohol, the ratio of the matrix of the reaction system can be increased without adjusting the pH of the buffer to improve the production efficiency.

Form of implementing the invention

Hereinafter, preferred embodiments of the oxidation method of the alcohol of the present invention will be specifically described based on examples and comparative examples. Further, when the sodium hypochlorite 5 hydrate used in the examples is dissolved in water to form an aqueous solution, the effective chlorine concentration is in the range of 10 to 30% and the pH is about 10 to 11.

[Example 1]

The alcohol was used in the form of (-)-menthol 1.56 g (10.0 mmol), the phase shifting catalyst was 0.170 g (0.50 mmol) of tetrabutylammonium hydrogen sulfate, and the nitroxyl radical catalyst was TEMPO 0.0157 g ( 0.10 mmol), the solution was dissolved in 30 mL of dichloromethane and placed in a reaction vessel. Thereafter, 3.30 g (20.1 mmol) of a powdery crystal of sodium hypochlorite 5 hydrate as an oxidizing agent was added in one portion while stirring at room temperature (25 ° C), and the reaction was stirred for 2 hours after the completion of the addition of the oxidizing agent. The reaction system temperature was raised by 0 ° C for about 30 minutes, and the reaction was started to 30 ° C at the end of 2 hours.

In the oxidation reaction of (-)-menthol, a reaction sample is taken out from the reaction system after the reaction is started for 2 hours by adding an oxidizing agent, and 4-chlorobenzotrifluoride is used as an internal standard substance by gas chromatography ( GC) An internal standard analysis of the reaction mixture confirmed that menthone was formed in a yield of 87%.

[Embodiment 2]

In addition to using 1.64 g (10.0 mmol) of 2,6-dimethyl-4-heptanol, 0.170 g (0.50 mmol) of tetrabutylammonium hydrogen sulfate and 0.0156 g (0.10 mmol) of TEMPO were dissolved in 30 mL of dichloromethane, and further, 4.94 g (30.0 mml) of powdery crystals of sodium hypochlorite 5 hydrate was used. The oxidation reaction was carried out in the same manner as in the above Example 1. The reaction temperature was raised by 10 ° C for about 45 minutes, and the reaction was started to 30 ° C at the end of 2 hours.

The internal standard analysis of the reaction liquid was carried out in the same manner as in Example 1, and it was confirmed that 2,6-dimethyl-4-heptanone was produced in a yield of 73%.

[Example 3]

In addition to the use of 1.-methyl-2-aza-adamantane-N-hydrocarbyloxy (commonly known as 1-Me-AZADO) 0.0162 g (0.10 mmol) in place of the TEMPO used in Example 2, and the use of sodium hypochlorite 5 hydrate powder An oxidation reaction was carried out in the same manner as in Example 2 except that 2.31 g (14.0 mm) of the crystal was crystallized. After the addition of the oxidizing agent for 30 minutes from the start of the reaction, internal standard analysis was carried out by GC in the same manner as in Example 1, and as a result, 2,6-dimethyl-4-heptanone was produced in a yield of 95%.

[Example 4]

1.30 g (10.0 mmol) of 2-octanol, 0.170 g (0.50 mmol) of tetrabutylammonium hydrogen sulfate and 0.021 g (0.13 mmol) of TEMPO were dissolved in 10 mL of dichloromethane, and placed in a reaction vessel, and the reaction vessel was placed therein. After the liquid temperature was cooled to 5 ° C, 2.00 g (12.2 mmol) of powdered crystals of sodium hypochlorite 5 hydrate was added in one portion with stirring, and the liquid temperature in the reaction vessel was maintained at 5 ° C for 15 minutes, and then GC analysis was carried out, and the raw material alcohol was completely obtained. Eliminate Lost. The addition of the oxidizing agent started the reaction for 30 minutes and then the reaction was terminated.

After the completion of the reaction, 20 mL of an aqueous sodium sulfite solution was added to the obtained reaction mixture to separate an organic phase. The aqueous phase was extracted with 30 mL of dichloromethane, and the mixture was washed with water (30 mL) and dried over anhydrous sodium sulfate. 0.42 g of the residue obtained by Kugelrohr distillation (45 torr baking temperature 120-130 ° C) gave 0.40 g of 2-octanone. The yield after isolation and purification was 95%.

[Examples 5 to 18]

The alcohol was 1.30 g (10.0 mmol) of 2-octanol, the oxidizing agent was 1.97 g (12.0 mmol) of sodium hypochlorite 5 hydrate, and the nitroxyl radical catalyst was 0.0156 g (0.10 mmol), and the same movement was carried out. The catalyst used was 0.05 mmol of tetrabutylammonium hydrogen sulfate (TBAS) or tetrabutylammonium bromide (TBAB), and 30 mL of the organic solvent shown in Table 1 was used, and the oxidizing agent shown in Table 1 was used and effective. Oxidation reaction was carried out under the same stirring conditions as in Example 1 under the conditions of chlorine concentration, presence or absence of a phase shifting catalyst, reaction temperature (room temperature: 20 to 30 ° C) and reaction time, and internal standard analysis by GC was carried out in the same manner as in Example 1. The yield of 2-octanone of the product of the oxidation reaction was determined.

The results are shown in Table 1.

[Comparative Example 1]

In addition to the use of the general commercial pH 13.1 and effective chlorine concentration 12.9 quality An oxidation reaction was carried out in the same manner as in the above Example 5 except that sodium hypochlorite 5 hydrate was used as the oxidizing agent, and the pH was adjusted at 5 ° C without adjusting the pH. The internal standard analysis was carried out by GC in the same manner as in Example 1, and the yield of 2-octanone was investigated.

The results are shown in Table 1.

[Comparative Example 2]

In addition to the use of a commercially available pH 13.1 and an effective chlorine concentration of 12.6% by mass of 6.73 g (12.0 mmol) of sodium hypochlorite aqueous solution, instead of sodium hypochlorite 5 hydrate as an oxidizing agent, and without the addition of TEMPO, the reaction temperature was 5 ° C as in the above Example 5. The oxidation reaction was carried out without adjusting the pH. The internal standard analysis was carried out by GC in the same manner as in Example 1, and the yield of 2-octanone was investigated.

The results are shown in Table 1.

[Embodiment 19]

A mixture of 13.0 g (100 mmol) of 2-octanol, 1.70 g (5.00 mmol) of tetrabutylammonium hydrogen sulfate, and 0.156 g (1.00 mmol) of TEMPO was placed in a reaction vessel, and the reaction vessel was not dissolved in an organic solvent. After the liquid temperature in the solution was cooled to 5 ° C, the liquid temperature was maintained at 5 to 10 ° C while stirring, and 33.7 g (120 mmol) of an aqueous solution having an effective chlorine concentration of 25.3 mass % obtained by dissolving sodium hypochlorite 5 hydrate crystals in water for 1 hour and 40 minutes. ) was dropped into the aforementioned mixture. After the completion of the dropping for 20 minutes (after 2 hours from the start of the dropping), the internal standard analysis was carried out by GC in the same manner as in Example 1, and as a result, 2-octanone was produced in a yield of 96%.

[Example 20]

An oxidation reaction was carried out in the same manner as in Example 5 except that 1-Me-AZADO 0.0163 g (0.10 mmol) was used as the nitron-based radical catalyst, and the TEMPO used in Example 5 was used instead. One hour after the initiation of the oxidation reaction, internal standard analysis was carried out by GC in the same manner as in Example 1, and as a result, 2-octanone was produced in a yield of more than 99%.

[Example 21]

1.31 g (10.1 mmol) of 1-octanol, 0.170 g (0.50 mmol) of tetrabutylammonium hydrogen sulfate, and 0.0156 g (0.10 mmol) of TEMPO were dissolved in 30 mL of dichloromethane, and placed in a reaction vessel, and the reaction vessel was placed therein. After the liquid temperature is cooled to 5 ° C, sodium hypochlorite 5 hydrate crystals are added with stirring. 1.81 g (11.0 mmol), and thereafter, the liquid temperature was directly maintained at 5 ° C, and the oxidation reaction was carried out by stirring. One hour after the initiation of the oxidation reaction, internal standard analysis was carried out by GC in the same manner as in Example 1 to give 1-octanal in a yield of 91%.

[Example 22]

1.10 g (10.1 mmol) of benzyl alcohol, 0.161 g (0.50 mmol) of tetrabutylammonium bromide, 0.0160 g (0.10 mmol) of TEMPO, and 1.22 g of m-dichlorobenzene (GC internal standard substance) were dissolved in dichloromethane 30 mL. After being placed in a reaction vessel, the liquid temperature in the reaction vessel was cooled to 5 ° C, and 1.99 g (12.1 mmol) of sodium hypochlorite 5 hydrate crystals were added thereto with stirring. Thereafter, the ice bath was removed and warmed to room temperature, and the reaction was carried out under stirring. . One hour after the initiation of the oxidation reaction, internal standard analysis was carried out by GC in the same manner as in Example 1, and it was confirmed that benzaldehyde was produced in a yield of 93%.

[Example 23]

1.31 g (10.1 mmol) of 3-octanol, 0.169 g (0.50 mmol) of tetrabutylammonium hydrogen sulfate, 0.0154 g (0.10 mmol) of TEMPO, and 1.55 g of 4-chlorobenzotrifluoride (GC internal standard substance) were dissolved. After 30 mL of dichloromethane, the reaction vessel was placed in a reaction vessel, and the temperature in the reaction vessel was cooled to 5 ° C. Then, 1.98 g (12.0 mmol) of sodium hypochlorite 5 hydrate crystals were added thereto with stirring, and then the temperature was raised to room temperature by removing the ice bath. The oxidation reaction is carried out with stirring. One hour after the initiation of the oxidation reaction, internal standard analysis was carried out by GC in the same manner as in Example 1 to confirm that 3-octanone was formed in a yield of 96%.

[Example 24]

1.31 g (10.1 mmol) of 3-octanol, 0.170 g (0.50 mmol) of tetrabutylammonium hydrogen sulfate, and 0.0155 g (0.10 mmol) of TEMPO were dissolved in 30 mL of dichloromethane, and placed in a reaction vessel, and the reaction vessel was placed therein. After the liquid temperature was cooled to 5 ° C, 1.98 g (12.0 mmol) of sodium hypochlorite 5 hydrate crystals were added thereto with stirring, and thereafter, the liquid temperature was directly maintained at 5 ° C, and an oxidation reaction was carried out with stirring. One hour after the initiation of the oxidation reaction, internal standard analysis by GC was carried out in the same manner as in Example 1, and as a result, 3-octanone was produced in a yield of 97%.

[Example 25]

1.30 g (10.0 mmol) of 3-octanol, 0.160 g (0.50 mmol) of tetrabutylammonium hydrogen sulfate, and 0.020 g (0.13 mmol) of TEMPO were dissolved in 10 mL of dichloromethane, and placed in a reaction vessel, and 0.2 mL of water was added. After the reaction vessel, the liquid temperature was cooled to 8 ° C, and 2.0 g (12.2 mmol) of sodium hypochlorite 5 hydrate crystals were added thereto with stirring, followed by stirring at 15 ° C for 40 minutes to carry out an oxidation reaction.

After the completion of the reaction, 20 mL of an aqueous solution of sodium sulfite was added to the obtained reaction mixture, and the organic phase was separated, and the organic phase was washed with water, dried over sodium sulfate, and the solvent was evaporated under reduced pressure to give 1.30 g of residue. 0.40 g of a residue obtained by Kogel roll distillation (65 torr, baking temperature 130-140 ° C) gave 0.38 g of a colorless transparent liquid. The obtained colorless transparent body was analyzed by GCMS, and the result contained 3-octyl ketone with a purity of 99.71% and 0.29%. 3-octanol. The yield of 3-octanone obtained by isolation was 96%.

[Example 26]

0.56 g (3.0 mmol) of 1-dodecanol, 0.051 g (0.15 mmol) of tetrabutylammonium hydrogen sulfate, and 0.005 g (0.03 mmol) of TEMPO were dissolved in 30 mL of dichloromethane, and placed in a reaction vessel, and the reaction vessel was placed. After the liquid temperature inside was cooled to 0 ° C, 1.2 g (7.3 mmol) of sodium hypochlorite 5 hydrate crystals were added, and the oxidation reaction was carried out with stirring. The oxidation reaction was started for 10 minutes and then returned to room temperature. After 1 hour, 1.2 g (7.3 mmol) of sodium hypochlorite 5 hydrate crystals were further added. After repeating this operation three times over 3 hours, the reaction was further stirred at room temperature for 9 hours. After the completion of the reaction, 20 mL of water was added to the reaction mixture, and the organic liquid was separated, and the obtained organic layer was dried over anhydrous magnesium sulfate. The residue obtained was purified by silica gel column chromatography to give 0.56 g of dodecanoic acid. The yield of the obtained dodecanoic acid was 93%.

[Comparative Example 3]

In the oxidation reaction using 1-Me-AZADO as a catalyst in Example 20, except that 6.78 g (12.0 mmol) of a sodium hypochlorite aqueous solution having a pH of 13.1 and an effective chlorine concentration of 12.6% by mass was used, instead of sodium hypochlorite 5 hydrate crystals, The oxidation reaction was carried out in the same manner as in Example 20 except that the reaction temperature was 5 ° C and the pH was not adjusted. Internal standard analysis by GC was carried out in the same manner as in Example 1, and as a result, 14% of 2-octanone was produced in one hour.

Claims (9)

An oxidation method of an alcohol characterized by the following general formula (1) (wherein R ¹ represents an alkyl group, an aryl group or an aralkyl group, and R ² represents an alkyl group, an aryl group, an arylalkyl group or a hydrogen atom) is oxidized to produce an alcohol of the following formula (2). In the method of oxidizing an alcohol of a carbonyl compound represented by the formula (wherein R ¹ represents an alkyl group, an aryl group or an aralkyl group, and R ³ represents an alkyl group, an aryl group, an aralkyl group, a hydrogen atom or a hydroxyl group), sodium hypochlorite is used. 5 hydrate as an oxidizing agent. The method for oxidizing an alcohol according to claim 1, wherein the sodium oxychloride 5 hydrate of the oxidizing agent is used as an aqueous solution or crystal having an effective chlorine concentration of 12% by mass or more. The method for oxidizing an alcohol according to claim 2, wherein the sodium oxychloride 5 hydrate of the oxidizing agent is used as an aqueous solution or crystal having an effective chlorine concentration of 20% by mass or more. The method for oxidizing an alcohol according to any one of claims 1 to 3, wherein the oxidizing agent consisting of the sodium hypochlorite 5 hydrate and the nitroxan group are free The base catalyst and/or the phase shifting catalyst are used together. The method for oxidizing an alcohol according to claim 4, wherein the nitroxide radical catalyst is a catalyst of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), 2-aza The adamantane-N-hydrocarbyloxy compound (AZADO) is a catalyst or a mixture of one or more selected from the group consisting of azabicyclo[3,3,1]decane-N-hydrocarbyloxy compounds. The method for oxidizing an alcohol according to claim 4, wherein the phase-shifting catalyst is a 4-stage ammonium salt, a 4-grade sulfonium salt, a polyethylene glycol, a crown ether, an alkyl sulfate, and an alkyl sulfonate. One or a mixture of two or more selected from the group consisting of an acid salt, an amphoteric surfactant, and the like. The method for oxidizing an alcohol according to any one of claims 1 to 6, wherein the oxidation of the alcohol is carried out in the presence of an organic solvent which dissolves the alcohol without being oxidized by the oxidizing agent. The method for oxidizing an alcohol according to any one of claims 1 to 6, wherein the oxidation of the alcohol is carried out in a solvent-free manner without using an organic solvent. The method for oxidizing an alcohol according to any one of claims 1 to 8, wherein the oxidation of the alcohol is carried out without adjusting the pH.