JP6434261B2 - Iodobenzamide type alcohol oxidation catalyst - Google Patents

Description

The present invention relates to a method for oxidizing alcohols using an iodobenzamide derivative as a catalyst.

In recent years, an alcohol oxidation reaction using a hypervalent iodine oxidizer based on 2-iodobenzoic acid or a monovalent iodine catalyst has been actively developed (Non-patent Document 1). A pentavalent oxidant (non-patent document 2) and a monovalent oxidation catalyst incorporating other functions such as a polymer-fixed reactant have also been developed (non-patent document 3).
On the other hand, some pentavalent analogs of 2-iodobenzoic acid esters and amides have been synthesized, and their reactivity as alcohol oxidizing agents has been shown (Non-Patent Documents 4 and 5).

Chem. Commun., 2086-2099 (2009) J. Org. Chem., 76, 1185-1197 (2011) Chem. Commun., 47, 1875-1877 (2011) Angew. Chem. Int. Ed., 42, 2194-2196 (2003) J. Org. Chem., 70, 6484-6491 (2005)

In the presence of oxone (a mixture of potassium persulfate, potassium hydrogensulfate, and potassium sulfate), a conventionally used catalyst such as 2-iodobenzoic acid, one having a substituent on its benzene ring, or 2-iodosulfonic acid is used. When heated at 70 ° C. with alcohols, the corresponding aldehyde is obtained from the primary alcohol and the corresponding ketone is obtained from the secondary alcohol. In these reactions, pentavalent iodine species are generated in the reaction system, which oxidizes alcohols. However, since pentavalent iodine compounds have explosive properties, it is dangerous to expose them to heating conditions even in catalytic amounts. That is, the problem to be solved by the present invention is to develop an iodine catalyst that can be used at a lower temperature.

2-Iodobenzoic acid is readily available. Therefore, an ester or amide can be easily synthesized by condensing the carboxy group with an easily prepared alcohol or amine. The present inventors have synthesized esters and amides using various alcohols and amines and studied their catalytic activities. As a result, the inventors succeeded in creating a catalyst capable of reacting at a low temperature (room temperature) and completed the present invention.
Hereinafter, the present invention will be described in detail.

In the present invention, unless otherwise specified, a halogen atom is a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc .; an alkyl group is methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, s-butyl A linear or branched C _1-6 alkyl group such as t-butyl; alkylene is a linear or branched C _1-6 alkylene group such as methylene, ethylene or propylene; an acyl group is A linear or branched C _2-6 alkyl-CO— group such as acetyl, propionyl, isobutyryl; etc .; an acyloxy group is a linear or branched C ₂₋ group such as acetyloxy, propionyloxy, isobutyryloxy, etc. ₆ alkyl -CO-O- groups; alkoxy groups include methoxy, ethoxy, propoxy etc. linear or branched C _1-6 alkyl -O- group; cycloalk The group, cyclopentyl, C _2-7 cycloalkyl groups such as cyclohexyl; and an aryl group, a phenyl, group a naphthyl; The alkylsulfonyl group, linear or branched C _1-6 alkyl A —SO ₂ — group; an arylsulfonyl group means an aryl-SO ₂ — group, respectively.

The present invention is an iodobenzamide type catalyst represented by the following general formula [1].
General formula
“In the formula, R ¹ represents a hydrogen atom or a halogen atom or a group selected from alkyl, alkoxy, acyl, acyloxy or nitro; R ² and R ³ are the same or different and each represents a hydrogen atom or an optionally substituted alkyl. , Cycloalkyl, alkylsulfonyl or arylsulfonyl group, or an alkylene group which may be substituted together, respectively.

The following are mentioned as a more specific iodobenzamide type | mold catalyst of this invention.

“In the formulas [1a] to [1d], R ¹ represents a hydrogen atom or a halogen atom or a group selected from alkyl, alkoxy, acyl, acyloxy or nitro; R ^2a may be protected. R ⁴ is an alkyl group or an aryl group, R ⁵ is an alkyl group, R ⁶ is a carboxyl group or 1,1 -Diphenylhydroxymethyl group, A means an alkylene group respectively. "

The present invention is also a method for oxidizing alcohols using a cooxidant in the presence of the iodobenzamide type catalyst represented by the above general formula [1].

Examples of the co-oxidant used here include inorganic oxidants such as potassium peroxymonosulfate and organic oxidants such as m-chloroperbenzoic acid, and oxone (a mixture of potassium persulfate, potassium hydrogensulfate and potassium sulfate) is preferred.
The usage-amount of a co-oxidant should just be 1-5 equivalent with respect to alcohol of a raw material.

  The solvent used here is not particularly limited as long as it does not adversely affect the reaction, and examples thereof include mixed solvents such as nitromethane / water, ethyl acetate / water, chloroform / water.

  The amount of the iodobenzamide type compound represented by the general formula [1] used here may be a catalytic amount, but is, for example, 0.05 to 0.5 equivalent, preferably 0.5 to the starting alcohol. What is necessary is just 0.5-0.3 equivalent.

In the oxidation method of the present invention, an ion pair reagent such as tetrabutylammonium hydrogen sulfate may be used. The amount of the ion pair reagent used may be 0.1 to 3.0 equivalents, preferably 0.1 to 1.0 equivalents, relative to the starting alcohol.

Oxidation of alcohols in the present invention in the presence of a 2-iodobenzoic acid amide type catalyst and a co-oxidant causes primary alcohols to carboxylic acids and secondary alcohols to ketones at a low temperature such as room temperature. Can be manufactured efficiently.

The iodobenzamide type catalyst of the present invention can be produced, for example, by the following method.

<Production method 1>

“In the formula, R ¹ represents a hydrogen atom or a halogen atom or a group selected from alkyl, alkoxy, acyl, acyloxy or nitro; R ² and R ³ are the same or different and each represents a hydrogen atom or an optionally substituted alkyl. , Cycloalkyl, alkylsulfonyl or arylsulfonyl group, or an alkylene group which may be substituted together, X represents a halogen atom such as a chlorine atom.

The compound of general formula [1] can be produced by reacting the compound of general formula [2] with the compound of general formula [3] in a solvent.

The solvent used in this reaction is not particularly limited as long as it does not adversely affect the reaction, and examples thereof include halogenated hydrocarbons such as methylene chloride, chloroform and dichloroethane. One or a mixture of two or more solvents can be used. May be used.
This reaction may be performed at 20 ° C. to 60 ° C. for 30 minutes to 12 hours.

  The compound of the general formula [2] may be purchased commercially or manufactured according to a known method. Moreover, the compound of general formula [1] can also be derived into another general formula [1] as shown below, for example.

<Production method 2>

“Wherein R ¹ represents a hydrogen atom or a halogen atom or a group selected from alkyl, alkoxy, acyl, acyloxy or nitro; R ⁵ represents an alkyl group, and A represents an alkylene group.

The compound of general formula [1c] can be produced by reacting the compound of general formula [1d] with the compound of general formula [4]. This reaction may be performed in the same manner as described in Production Method 1.

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto.

Example 1
<Catalyst synthesis>

A solution of 2-iodobenzoyl chloride (799 mg, 3 mmol) in methylene chloride (3 mL) was added to a solution of isopropylamine (213 mg, 3.6 mmol) and triethylamine (911 mg, 9 mmol) in methylene chloride (7 mL) at 0 ° C. and then at room temperature. Stir for hours. The reaction mixture was diluted with ethyl acetate (50 mL), washed with 10% hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution, water and saturated brine, dried and concentrated. The residue was recrystallized from ethyl acetate-hexane to obtain colorless needle-like 2-iodo-N-isopropylbenzamide [Compound 1] (580 mg, 67%).
Melting point: 134-135 ° C
Similarly, the following compounds were obtained.

・ N-ethyl-2-iodobenzamide [Compound 2]
Colorless plate crystals (recrystallization solvent: ethyl acetate-hexane). Melting point: 119-120 ° C

・ N-tert-butyl-2-iodobenzamide [Compound 3]
Colorless needle crystals (recrystallization solvent: ethyl acetate-hexane). Melting point: 121.5-123 ° C

2-iodo-N-tert-pentylbenzamide [Compound 4]
Colorless needle crystals (recrystallization solvent: chloroform-hexane). Melting point: 120-122 ° C

2-iodo-N- (1-methylhexyl) benzamide [Compound 5]
Colorless powder (recrystallization solvent: chloroform-hexane). Melting point: 79-80.5 ° C

・ N-cyclohexyl-2-iodobenzamide [Compound 6]
Colorless needle crystals (recrystallization solvent: ethyl acetate-hexane). Melting point: 147-148 ° C

2-iodo-N-phenethylbenzamide [Compound 7]
Colorless columnar crystals (recrystallization solvent: ethyl acetate-hexane). Melting point: 124-125 ° C

・ 2- (2-iodobenzamido) ethyl acetate [Compound 8]
Colorless needle crystals (recrystallization solvent: chloroform-hexane). Melting point: 119-121 ° C

・ Methyl 2- (2-iodobenzamido) acetate [Compound 9]
Slightly yellow needle crystals (recrystallization solvent: chloroform-hexane). Melting point: 105-107 ° C

・ Methyl 2- (2-iodobenzamido) propanoate [Compound 10]
Colorless needle crystals (recrystallization solvent: chloroform-hexane). Melting point: 101-102.5 ° C

2-iodo-N- (methylsulfonyl) benzamide [Compound 11]
Colorless needle crystals (recrystallization solvent: chloroform-hexane). Melting point: 126-128 ° C

2-iodo-N- (phenylsulfonyl) benzamide [Compound 12]
Colorless plate crystals (recrystallization solvent: chloroform). Melting point: 108-110 ° C

Example 2
<Catalyst synthesis 2>

A solution of 2-iodobenzoyl chloride (799 mg, 3 mmol) in methylene chloride (3 mL) was added to a solution of 2-amino-2-methylpropanoic acid hydrochloride (553 mg, 3.6 mmol) and triethylamine (911 mg, 9 mmol) in methylene chloride (7 mL). The mixture was added at 0 ° C. and then stirred at room temperature for 1 hour. The reaction mixture was diluted with ethyl acetate (50 mL), washed with 10% hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution, water and saturated brine, dried and concentrated. The residue was purified by silica gel column chromatography to obtain methyl 2- (2-isobenzamido-2-methylpropanoate [Compound 13] (889 mg, 85%).
Colorless needle crystals (recrystallization solvent: ethyl acetate-hexane).
Melting point: 125-127 ° C

Compound 13 (889 mg, 2.56 mmol) and lithium hydroxide monohydrate (430 mg, 10.24 mmol) were dissolved in a mixed solvent (28 mL) of tetrahydrofuran / methanol / water (25: 8: 8) and stirred at room temperature for 30 minutes. The reaction was diluted with water (60 mL) and acidified with 10% hydrochloric acid. Extracted with ethyl acetate. The extract was dried and concentrated to give 2- (2-isobenzamido-2-methylpropanoic acid [Compound 14] (836 mg, 98%).
Colorless needle crystal (recrystallization solvent: ethyl acetate-hexane)
Melting point: 206-207 ° C.

In addition to compound 14 (836 mg, 2.51 mmol) and thionyl chloride (3.1 mL), the mixture was heated to reflux for 2 hours and then concentrated to give 2- (2-iodobenzamido) -2-methylpropanoyl chloride [14a].
Butylamine (220 mg, 3.01 mmol) and triethylamine (762 mg, 7.53 mmol) were added to a solution of compound 14a in methylene chloride (8 mL) at 0 ° C., and the mixture was stirred at room temperature for 1 hour. The reaction mixture was diluted with ethyl acetate (50 mL), washed with 10% hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried and concentrated. The residue was recrystallized from ethyl acetate-hexane to obtain colorless needle-like N- (1-butylcarbamoyl-1-methylethyl) -2-iodobenzamide [Compound 15] (788 mg, 80%).
Melting point 134-135 ° C.

<Catalyst synthesis 3>
Example 3

2-Iodo-5-methoxybenzoic acid (471 mg, 1.69 mmol) was added to thionyl chloride (2.1 mL), heated under reflux for 2 hours, and then concentrated to obtain 2-iodo-5-methoxybenzoyl chloride. Next, isopropylamine (120 mg, 2.03 mmol) and triethylamine (513 mg, 5.07 mmol) were added to a solution of 2-iodo-5-methoxybenzoyl chloride in methylene chloride (5.6 mL) at 0 ° C., and the mixture was stirred at room temperature for 1 hour. The reaction mixture was diluted with ethyl acetate (50 mL), washed with 10% hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution, water and saturated brine, dried and concentrated. The residue was recrystallized from chloroform-hexane to obtain colorless needle-like 2-iodo-N-isopropyl-5-methoxybenzamide [Compound 16] (402 mg, 75%).

Melting point: 147-148.5 ° C
¹ H-NMR (400 MHz, CDCl ₃ ) δ: 7.68 (1H, d, J = 8.7Hz), 6.96 (1H, d, J = 3.2Hz), 6.68 (1H, dd, J = 8.7,3.2Hz) , 5.59 (1H, brd, J = 6.4Hz), 4.29 (1H, m), 3.80 (3H, s), 1.29 (6H, d, J = 6.9Hz).
Similarly, the following compounds were obtained.

・ 5-chloro-2-iodo-N-isopropylbenzamide [Compound 17]

Colorless needle crystal (recrystallization solvent: chloroform-hexane), melting point: 160.5-162 ° C
¹ H-NMR (400 MHz, CDCl ₃ ) δ: 7.76 (1H, d, J = 8.2Hz), 7.37 (1H, d, J = 2.3Hz), 7.08 (1H, dd, J = 8.2,2.3Hz) , 5.54 (1H, brs), 4.29 (1H, m), 1.29 (6H, d, J = 6.4Hz).

2-iodo-N-isopropyl-5-methylbenzamide [Compound 18]

Colorless needle crystals (recrystallization solvent: chloroform-hexane), melting point: 147-149 ° C
¹ H-NMR (400 MHz, CDCl ₃ ) δ: 7.69 (1H, d, J = 7.8Hz), 7.21 (1H, d, J = 1.8Hz), 6.90 (1H, dd, J = 7.8,1.8Hz) , 5.57 (1H, brd, J = 4.6Hz), 4.29 (1H, m), 2.31 (3H, s), 1.28 (6H, d, J = 6.4Hz).

・ Methyl 4-iodo-3- (isopropylcarbamoyl) benzoate [Compound 19]

Colorless columnar crystals (recrystallization solvent: chloroform-hexane), melting point: 170-171.5 ° C.
¹ H-NMR (400 MHz, CDCl ₃ ) δ: 8.49 (1H, d, J = 1.4Hz), 8.01 (1H, dd, J = 7.8,1.4Hz), 7.42 (1H, d, J = 7.8Hz) , 5.64 (1H, brd, J = 7.3Hz), 4.30 (1H, m), 3.93 (3H, s), 1.30 (6H, d, J = 6.4Hz).

2-iodo-N-isopropyl-5-nitrobenzamide [Compound 20]

Colorless needle crystals (recrystallization solvent: chloroform-hexane), melting point: 196-198 ° C
¹ H-NMR (400 MHz, CDCl ₃ ) δ: 8.19 (1H, d, J = 2.7Hz), 8.07 (1H, d, J = 8.7Hz), 7.92 (1H, dd, J = 8.7,2.7Hz) , 5.64 (1H, brd, J = 4.6Hz), 4.33 (1H, m), 1.32 (6H, d, J = 6.4Hz).

2-iodo-N-isopropyl-4-methoxybenzamide [Compound 21]

Colorless needle crystals (recrystallization solvent: chloroform-hexane), melting point: 132.5-135 ° C
¹ H-NMR (400 MHz, CDCl ₃ ) δ: 7.37 (1H, d, J = 2.7Hz), 7.35 (1H, d, J = 8.2Hz), 6.89 (1H, dd, J = 8.2,2.7Hz) , 5.58 (1H, brd, J = 5.0Hz), 4.28 (1H, m), 3.80 (3H, s), 1.28 (6H, d, J = 6.4Hz).

2-iodo-N-isopropyl-3-methoxybenzamide [Compound 22]

Colorless columnar crystals (recrystallization solvent: chloroform-hexane), melting point: 136-137.5 ° C
¹ H-NMR (400 MHz, CDCl ₃ ) δ: 7.31 (1H, t, J = 7.8Hz), 6.96 (1H, d, J = 7.8Hz), 6.83 (1H, d, J = 7.8Hz), 5.54 (1H, brd, J = 5.5Hz), 4.30 (1H, m), 3.90 (3H, s), 1.28 (6H, d, J = 6.4Hz).

Example 4
<Oxidation of primary alcohol>

3-Phenylpropanol (68 mg, 0.5 mmol) was added to 2-iodo-N-isopropylbenzamide [Compound 1] (43 mg, 0.15 mmol) and tetrabutylammonium hydrogen sulfate (170 mg, 0.5 mmol) in nitromethane (1.6 mL) and water (0.6 mL) was added to the mixture followed by oxone (768 mg, 1.25 mmol) at room temperature (25 ° C.). After 20 hours, the reaction mixture was diluted with ethyl acetate ((50 mL), water (10 mL) and saturated aqueous sodium thiosulfate solution (15 mL). After separation into two layers, the ethyl acetate diluted layer was extracted with saturated aqueous sodium bicarbonate solution. The extract was acidified with 10% hydrochloric acid and extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate and evaporated under reduced pressure to remove phenylpropionic acid (68 mg, 90% On the other hand, the ethyl acetate diluted layer was washed with saturated brine and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to recover 2-iodo-N-isopropylbenzamide (39 mg, 91%). did.

Example 5
Tetradecan-1-ol was used in place of 3-phenylpropanol in Example 4 and an oxidation reaction was performed for 24 hours to obtain tetradecanoic acid in a yield of 82%.

Example 6
Instead of 3-phenylpropanol in Example 4, (4-nitrophenyl) methanol was used and the oxidation reaction was carried out for 24 hours to obtain 4-nitrobenzoic acid in a yield of 82%.

Example 7
Instead of 3-phenylpropanol in Example 4, (4-chlorophenyl) methanol was used and the oxidation reaction was carried out for 24 hours to obtain 4-chlorobenzoic acid in a yield of 74%.

Example 9

3-phenylpropanol (68 mg, 0.5 mmol) was added to N- (1-butylcarbamoyl-1-methylethyl) -2-iodobenzamide [compound 15] (43 mg, 0.15 mmol) and tetrabutylammonium hydrogen sulfate (170 mg, 0.5 mmol). mmol) of nitromethane (1.6 mL) / water (0.6 mL), and then oxone (768 mg, 1.25 mmol) was added at room temperature (25 ° C.). After 20 hours, the reaction was diluted with ethyl acetate (50 mL), water (10 mL) and saturated aqueous sodium thiosulfate (15 mL). After separation into two layers, the ethyl acetate diluted layer was extracted with a saturated aqueous sodium bicarbonate solution. The extract was acidified with 10% hydrochloric acid and extracted with ethyl acetate, the extract was dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain phenylpropionic acid (66 mg, 90%). On the other hand, the ethyl acetate diluted layer was washed with saturated brine and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to give N- (1-butylcarbamoyl-1-methylethyl) -2-iodobenzamide (40 mg, 93%) was recovered.

Example 10
<Oxidation of secondary alcohol>

Diphenylmethanol (100 mg, 0.54 mmol) was added to 2-iodo-N-isopropylbenzamide [Compound 1] (47 mg, 0.16 mmol) and tetrabutylammonium hydrogensulfate (184 mg, 0.54 mmol) in nitromethane (1.6 mL) and water (0.6 mL) and then oxone (835 mg, 1.36 mmol) was added at room temperature (25 ° C.). After 12 hours, the reaction solution was diluted with ethyl acetate (50 mL), washed successively with water, saturated aqueous sodium thiosulfate solution, saturated aqueous sodium hydrogen carbonate solution and saturated brine, and then dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. . The residue was purified by silica gel column chromatography to obtain benzophenone (93 mg, 94%). In addition, 2-iodo-N-isopropylbenzamide (42 mg, 89%) was recovered.

Example 11
The acetophenone was obtained in a yield of 70% by using 1-phenylethanol in place of diphenylmethanol of Example 10 and carrying out an oxidation reaction for 14 hours.

Example 12
Using 4-phenylbutan-2-ol in place of diphenylmethanol of Example 10 and carrying out an oxidation reaction for 30 hours, 4-phenylbutan-2-one was obtained in a yield of 70%.

Example 13

Diphenylmethanol (92 mg, 0.5 mmol) was added to N- (1-butylcarbamoyl-1-methylethyl) -2-iodobenzamide [Compound 15] (58 mg, 0.15 mmol) and tetrabutylammonium hydrogensulfate (170 mg, 0.5 mmol). Was added to a mixture of nitromethane (1.6 mL) and water (0.6 mL), followed by oxone (765 mg, 1.25 mmol) at room temperature (25 ° C.). After 13 hours, the reaction mixture was diluted with ethyl acetate (50 mL), washed successively with water, saturated aqueous sodium thiosulfate solution, saturated aqueous sodium bicarbonate solution, and saturated brine, and then dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure. did. The residue was purified by silica gel column chromatography to obtain benzophenone (89 mg, 98%). In addition, N- (1-butylcarbamoyl-1-methylethyl) -2-iodobenzamide (44 mg, 76%) was recovered.

Example 14
Compound 3 (0.1 equivalent) was used in place of compound 1 (0.3 equivalent) in Example 10, and the oxidation reaction was performed for 34 hours to obtain benzophenone in a yield of 98%.

Example 15
Compound 13 (0.3 equivalent) was used instead of compound 1 (0.3 equivalent) in Example 10 and the oxidation reaction was carried out for 16 hours to obtain benzophenone in a yield of 97%.

Example 16
<Oxidation of secondary alcohol 2>

Diphenylmethanol (92 mg, 0.5 mmol) with 2-iodo-N-isopropyl-5-methoxybenzamide [Compound 16] (48 mg, 0.15 mmol) and tetrabutylammonium hydrogen sulfate (170 mg, 0.5 mmol) in nitromethane (1.6 mL) -Added to water (0.6 mL) followed by Oxone (768 mg, 1.25 mmol) at room temperature (25 ° C). After 6 hours, the reaction solution was diluted with ethyl acetate (50 mL), washed successively with water, saturated aqueous sodium thiosulfate solution, and saturated aqueous sodium hydrogen carbonate solution, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography to obtain benzophenone (88 mg, 97%). In addition, 2-iodo-N-isopropyl-5-methoxybenzamide (41 mg, 85%) was recovered.

Example 17
Compound 17 (0.3 equivalent) was used instead of compound 16 (0.3 equivalent) in Example 16, and the oxidation reaction was performed for 18 hours to obtain benzophenone in a yield of 98%.

Example 18
Compound 18 (0.3 equivalent) was used instead of compound 16 (0.3 equivalent) in Example 16, and the oxidation reaction was carried out for 10 hours to obtain benzophenone in a yield of 98%.

Example 19
Compound 19 (0.3 equivalent) was used in place of compound 16 (0.3 equivalent) in Example 16, and an oxidation reaction was performed for 23 hours to obtain benzophenone in a yield of 96%.

Example 20
Compound 20 (0.3 equivalent) was used instead of compound 16 (0.3 equivalent) in Example 16, and the oxidation reaction was carried out for 46 hours to obtain benzophenone in a yield of 98%.

Example 21
Compound 21 (0.3 equivalent) was used in place of compound 16 (0.3 equivalent) in Example 16, and the oxidation reaction was carried out for 13 hours to obtain benzophenone in a yield of 98%.

Example 22
Compound 22 (0.3 equivalent) was used in place of compound 16 (0.3 equivalent) in Example 16, and an oxidation reaction was performed for 23 hours to obtain benzophenone in a yield of 99%.

The 2-iodobenzoic acid amide type catalyst of the present invention can be used in the oxidation process of alcohols in the production of fine chemicals such as pharmaceuticals and agricultural chemicals, and can achieve the construction of a green industrial plant with little waste.

Claims (4)

General formula
“In the formula, R ¹ represents a hydrogen atom or a halogen atom or a group selected from alkyl, alkoxy, acyl, acyloxy or nitro; R ² and R ³ are the same or different and each represents a hydrogen atom or an optionally substituted alkyl. , Cycloalkyl, alkylsulfonyl or phenylsulfonyl group, or an alkylene group which may be substituted together, respectively.
A method for oxidizing alcohols, characterized by using an iodobenzamide type catalyst represented by the formula (1) and a cooxidant. The method for oxidizing alcohols according to claim 1 , wherein R ^{1 of the} iodobenzamide type catalyst is a hydrogen atom. How oxidation of alcohols according to claim 1 R ¹ of iodobenzamide catalyst is an alkoxy group. The method for oxidizing an alcohol according to any one of claims 1 to ³ , wherein R ^{2 of the} iodobenzamide type catalyst is a hydrogen atom, and R ³ is an optionally substituted alkyl, cycloalkyl, alkylsulfonyl, or arylsulfonyl group.