JP2006176433A - Pyruvic acid amide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound high in safety, free of odor in itself, and having high deodorizing performance enough to efficiently eliminate odor of mercaptans and pyridines, to provide a method for efficiently producing the compound, and to provide a deodorizer containing the same. <P>SOLUTION: [1] The compound is a pyruvic acid amide of the general formula(1)( wherein, R<SP>1</SP>and R<SP>2</SP>are each H, an alkyl, alkenyl or hydroxyalkyl, or may be bound to each other to form a cyclic structure ). [2] The method for producing the compound comprises carrying out an acetalization of a pyruvic acid lower alkyl ester followed by amidation and then deacetalization. [3] The deodorizer contains the pyruvic acid amide of general formula(1). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to pyruvate amides. Specifically, the present invention relates to novel pyruvate amides, an efficient production method thereof, and a deodorant containing the same.

Conventional deodorizers used for the purpose of removing odors from amines and mercaptans include methacrylic acid esters and aldehydes. In methacrylic acid esters, lauryl methacrylate is generally used as a deodorant, and in aldehydes, benzaldehyde, citral and the like are generally used as a deodorant.
However, lauryl methacrylate has a weak deodorizing effect against the odors of amines and mercaptans, and benzaldehyde, citral, etc. can deodorize amines relatively efficiently, but the odor of mercaptans The deodorizing effect is not enough.

On the other hand, a deodorant (Patent Document 1) containing pyruvic acid ester as an active ingredient and a deodorizer (Patent Document 2) containing an α-diketone compound as an active ingredient are known.
However, although pyruvate and α-diketone compounds have a deodorizing effect on amines, mercaptans and pyridines, pyruvate has poor stability in aqueous solution, and pyruvate and α-diketone. The compound itself has a strong odor and has been a problem for use as a deodorant.
Therefore, a deodorant that has high stability, has no odor of the deodorant itself, and can efficiently remove odors such as amines, mercaptans, and pyridines has been desired.

JP-A-6-121822 JP-A-8-275997

  The present invention is highly stable, has no odor of itself, can efficiently remove odors such as amines, mercaptans and pyridines, and has excellent deodorizing performance, and an efficient production method thereof It is another object of the present invention to provide a deodorant containing the same.

The present inventors have found that pyruvic amides having a specific structure are novel compounds not described in the literature, have no odor of themselves, have high stability, and are amines, mercaptans and pyridines. It has been found that odors such as can be efficiently removed.
Moreover, it discovered that this pyruvic amide could be efficiently manufactured according to a specific process.
That is, the present invention
[1] General formula (1)

（式中、Ｒ¹及びＲ²は、それぞれ独立に、水素原子、アルキル基、アルケニル基又はヒドロキシアルキル基を示し、また、互いに結合して環構造を形成していてもよい。）で表されるピルビン酸アミド類、

(Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkenyl group or a hydroxyalkyl group, and may be bonded to each other to form a ring structure). Pyruvate amides,

[2] An alcohol is reacted with a lower alkyl ester of pyruvic acid under acidic conditions to acetalize the carbonyl group at the 2-position of the lower alkyl ester of pyruvic acid, and then under general conditions (2)

（式中、Ｒ¹及びＲ²は、それぞれ独立に、水素原子、アルキル基、アルケニル基又はヒドロキシアルキル基を示し、また、互いに結合して環構造を形成していてもよい。）で表されるアミン類を反応させて酸アミド体を得た後、水素雰囲気下で加水素分解して脱アセタール化する、前記一般式（１）で表されるピルビン酸アミド類の製造方法、及び
〔３〕前記（１）のピルビン酸アミド類を含有する消臭剤、
を提供する。

(Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkenyl group or a hydroxyalkyl group, and may be bonded to each other to form a ring structure). A method for producing pyruvic acid amides represented by the general formula (1), wherein an acid amide compound is obtained by reacting the amines, followed by hydrogenolysis in a hydrogen atmosphere and deacetalization; and [3 A deodorant containing the pyruvate amide of (1),
I will provide a.

  According to the present invention, it is a novel compound not described in any literature, has no odor of itself, has high stability, and can efficiently remove odors such as amines, mercaptans and pyridines. The present invention can provide pyruvic acid amides excellent in deodorizing performance that can be used for a wide range of uses, an efficient production method thereof, and a deodorant containing the same.

  The pyruvic amides of the present invention are novel compounds not yet described in literature, and have a structure represented by the following general formula (1).

In the general formula (1), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or a hydroxyalkyl group, and may be bonded to each other to form a ring structure.
As said alkyl group, a C1-C20 thing is preferable and a C2-C18 thing is more preferable. The alkyl group may be linear, branched or cyclic.
Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various octyl groups, various decyl groups, various dodecyl groups, various tetradecyl groups, Examples include various hexadecyl groups, various octadecyl groups, cyclopentyl groups, cyclohexyl groups, and cyclooctyl groups.

As an alkenyl group, a C2-C20 thing is preferable and a C3-C18 thing is more preferable. The alkenyl group may be linear, branched or cyclic.
Specific examples of the alkenyl group include allyl group, propenyl group, various butenyl groups, various octenyl groups, various decenyl groups, various dodecenyl groups, various tetradecenyl groups, various hexadecenyl groups, various octadecenyl groups, cyclopentenyl group, cyclohexenyl group, A cyclooctenyl group etc. are mentioned.

As a hydroxyalkyl group, a C1-C20 thing is preferable and a C2-C18 thing is more preferable. Specific examples of the hydroxyalkyl group include a group in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group, and specifically, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group. Group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group and the like.
Examples of the group having a ring structure in which R ¹ and R ² are bonded to each other and N is a hetero atom include a 1-pyrrolidinyl group, a piperidino group, a hexamethyleneimino group, and the like.
R ¹ and R ² are preferably those in which any of them is a hydrogen atom from the viewpoint of solubility of pyruvic acid amides in water.

  Specific examples of the pyruvic acid amides of the present invention include N-ethylpyruvic acid amide, N-2-hydroxyethylpyruvic acid amide, N-propylpyruvic acid amide, N-3-hydroxypropylpyruvic acid amide, N-butyl. Pyruvic acid amide, N-hexyl pyruvic acid amide, N-octyl pyruvic acid amide, N-decyl pyruvic acid amide, N-lauryl pyruvic acid amide, N-myristyl pyruvic acid amide, N-palmityl pyruvic acid amide, N-stearyl Examples include pyruvic acid amide, N-cyclopentyl pyruvic acid amide, N-cyclohexyl pyruvic acid amide, N-allyl pyruvic acid amide, N-oleyl pyruvic acid amide, N-cyclopentenyl pyruvic acid amide, N-cyclohexenyl pyruvic acid amide and the like. It is done.

Although there is no restriction | limiting in particular about the manufacturing method of pyruvic amides of this invention represented by General formula (1), According to the method of this invention, it can manufacture efficiently.
In the method of the present invention, first, an alcohol is reacted with a lower alkyl ester of pyruvic acid under acidic conditions to acetalize the carbonyl group at the 2-position of the lower alkyl ester of pyruvic acid. This reaction formula is shown below.

（Ｒはメチル基、エチル基等の低級アルキル基、Ａはアルコール残基を示す。）

(R represents a lower alkyl group such as a methyl group or an ethyl group, and A represents an alcohol residue.)

In this reaction, benzyl alcohol is usually preferably used as the alcohol (4) used for acetalization. The amount of the alcohols (4) is preferably 2 to 3 mol, more preferably 2 to 2.2 mol, per 1 mol of pyruvic acid lower alkyl ester (3).
The acetalization reaction is carried out under acidic conditions, and as the acid, for example, p-toluenesulfonic acid, methanesulfonic acid, boron trifluoride ether complex or the like is used. These acids can be used alone or in combination of two or more. Among these, boron trifluoride ether complex is preferable. The amount used is preferably 1 to 3 mol, more preferably 1 to 2 mol, per 1 mol of pyruvic acid lower alkyl ester (3).
This reaction can be carried out in a solvent such as ether or tetrahydrofuran, but is preferably carried out without a solvent. The reaction temperature is usually −10 to 30 ° C., preferably 0 to 25 ° C. Although reaction time changes also with conditions, such as reaction temperature, about 30 minutes-about 2 hours are preferable normally. The end point of the reaction can be confirmed, for example, by gas chromatography.
In this way, an acetalized product (5) of pyruvic acid lower alkyl ester can be obtained.

  Next, the acetalized product (5) of the obtained lower alkyl ester of pyruvic acid was subjected to the general formula (2) under alkaline conditions.

（式中、Ｒ¹及びＲ²は、前記と同じである。）
で表されるアミン類を反応させて、酸アミド体を得る。この反応式を次に示す。

(In the formula, R ¹ and R ² are the same as described above.)
Is reacted to obtain an acid amide compound. This reaction formula is shown below.

（Ｒ¹、Ｒ²及びＡは、前記と同じである。）

(R ¹ , R ² and A are the same as above.)

The reaction between the acetalized product (5) and the amines (2) is performed under alkaline conditions. As the alkali, alkali metal alkoxides such as sodium mitoxide, sodium ethoxide, potassium methoxide and potassium ethoxide, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and the like can be used. These alkalis can be used alone or in combination of two or more. The amount used is preferably 0.01 to 40 mol and more preferably 10 to 30 mol with respect to 1 mol of the acetalized product.
Specific examples of the amines (2) include ethylamine, ethanolamine, propylamine, propanolamine, butylamine, hexylamine, octylamine, decylamine, laurylamine, myristylamine, palmitylamine, stearylamine, cyclopentylamine, cyclohexylamine , Allylamine, oleylamine, cyclopentenylamine, cyclohexenylamine and the like.
The amount of amines (2) used in this reaction is preferably 1 to 3 moles, more preferably 1.5 to 2.5 moles, per mole of acetalized product (5) of pyruvic acid lower alkyl ester.

Examples of the solvent used in this reaction include alcohols such as methanol, ethanol and isopropanol, hydrocarbons such as toluene and xylene, ethers such as diethyl ether and tetrahydrofuran, and the like. Among these, alcohols are preferable, and ethanol is particularly preferable. As a quantity of a solvent, 50-150 mass parts is preferable with respect to a total of 100 mass parts of an acetalization body (5) and amines (2), and 80-120 mass parts is more preferable.
Although reaction temperature changes also with the solvent to be used, it is 10-50 degreeC normally, and 20-40 degreeC is preferable. Although reaction time changes also with conditions, such as reaction temperature, about 6 to 24 hours are preferable normally. The end point of the reaction can be confirmed, for example, by gas chromatography.
In this way, an acetalized form (6) of pyruvic acid amides which are acid amides can be obtained.

  Next, the obtained acetalized pyruvate amide (6) is subjected to hydrogenolysis in a hydrogen atmosphere to deacetalize to thereby obtain a pyruvate amide represented by the general formula (1). Obtainable. This reaction formula is shown below.

（Ｒ¹、Ｒ²及びＡは、前記と同じである。）

(R ¹ , R ² and A are the same as above.)

In this hydrogenation reaction, a catalyst is used. As this catalyst, 5 mass% Pd / C, 10 mass% Pd / C, 4.5 mass% Pd-0.5 mass% Pt / C etc. are mentioned, for example. In these, 4.5 mass% Pd-0.5 mass% Pt / C is preferable.
The amount of the catalyst to be used is preferably 10 to 30 parts by mass, more preferably 15 to 25 parts by mass with respect to 100 parts by mass of the acetalized product of pyruvate amides (6).
As the solvent, alcohols such as methanol and ethanol can be used, but ethanol is more preferable. As a solvent amount, 100-2000 mass parts is preferable with respect to 100 mass parts of acetalization body (6) of pyruvic amides, and 500-1000 mass parts is more preferable.
The reaction pressure is usually from atmospheric pressure to 1 MPa, preferably from 0.3 to 0.6 MPa. Although reaction temperature changes also with the solvent to be used, it is 10-50 degreeC normally, and 20-40 degreeC is preferable. Although reaction time changes also with conditions, such as reaction temperature, about 6 to 24 hours are preferable normally. The end point of the reaction can be confirmed, for example, by gas chromatography.
Thus, the target pyruvic amides represented by the general formula (1) can be produced.

The pyruvate amides represented by the general formula (1) of the present invention exhibit an excellent deodorizing effect on amines, mercaptans, pyridines and the like.
The deodorant of this invention contains pyruvic amides represented by general formula (1). The content of the pyruvic amides varies depending on the concentration of deodorized amines, mercaptans, pyridines, etc., but it may be contained in an amount of 0.001% by mass or more based on the product used as the deodorant. Preferably, it is made to contain in 0.01-100.0 mass%.
The deodorizer of the present invention may contain other deodorizer along with the pyruvate amides. Furthermore, additives such as an antioxidant, a pH adjuster, a preservative, a fragrance, a surfactant, a dye, and an ultraviolet absorber, which are added to a normal deodorant, can also be contained. Moreover, the form of a deodorizer can be made into a liquid form, a powder form, a gel form, a granular form, etc. according to the intended purpose.
There is no restriction | limiting in particular about the usage method of the deodorizer of this invention. For example, it can be used by a method of mixing with a fragrance in various fragrances, a method of blending in an aerosol product, or the like for a kitchen odor generated around the kitchen or a bad smell in the toilet. Moreover, the deodorizer of this invention can be utilized for the deodorization of odors, such as a sewage treatment plant, a garbage disposal plant, and a livestock house, besides the malodor in a refrigerator.

In the following Examples and Comparative Examples, “parts” and “%” are “parts by mass” and “mass%” unless otherwise specified.
Example 1 [Production of N-2-hydroxyethylpyruvic acid amide (1-a)]
The reaction formula in this production is shown below.

Into a 500 mL four-necked flask, 100.00 g (0.861 mol) of ethyl pyruvate (3-a) and 186.26 g (1.722 mol) of benzyl alcohol (4-a) were added and stirred to 0 ° C. Cooled down. Boron trifluoride ether complex 122.23 g (0.861 mol) was added dropwise to the reaction solution over 15 minutes. The reaction temperature after completion of the dropwise addition was 10 ° C. Then, it heated up to room temperature and stirred at room temperature for 1 hour. The reaction solution was dropped into 2 L of a saturated sodium hydrogen carbonate solution over 2 hours, and the separated upper layer was collected. The upper layer (276.17 g) was subjected to simple distillation (column top 68 ° C., column bottom 120 ° C., 36 Pa) to remove the low boiling portion, and as a brown oil remaining in the flask, the benzyl acetal compound (5-a) 87.66 g (purity 91.5%) was obtained.
In a 1 L four-necked flask, 87.66 g (0.279 mol) of the obtained benzyl acetal compound (5-a), ethanol (143 mL), 34.08 g (0.558 mol) of monoethanolamine (2-a) were added. In addition, the mixture was stirred at room temperature for 5 minutes. 18.97 g (0.056 mol) of a 20% sodium ethoxide ethanol solution was added dropwise over 5 minutes, followed by stirring at room temperature for 24 hours. Ion exchange water (500 mL) and hexane (100 mL) were added, and the upper layer was washed with a pH 6.86 buffer until the aqueous layer became neutral. The upper organic solvent was removed under reduced pressure to obtain 78.49 g (purity 94.9%) of an amide compound (6-a) as a brown oily substance.
To a 1 L hydrogenation flask, 78.49 g of amide compound (6-a), 4.5% Pd-0.5% Pt / C 14.88 g and ethanol (750 mL) were added, and under a hydrogen atmosphere (0.45 MPa), Stirring was performed at room temperature for 8 hours. Ion exchange water (50 mL) was added and the catalyst was filtered. The solvent was removed under reduced pressure, and ion-exchanged water (100 mL) and ethyl acetate (100 mL) were added to the resulting colorless transparent oil to separate the layers. The lower layer water was removed under reduced pressure, and N-2-hydroxyethyl was removed. 3.86 g (purity 94.5%) of pyruvate amide (1-a) was obtained as a colorless transparent oil.

The measurement results of ¹ H-NMR, ¹³ C-NMR and IR of the obtained compound N-2-hydroxyethylpyruvic acid amide (1-a) are shown below.
¹ H-NMR (400 MHz, CDCl ₃ ): δ (ppm)
7.40 (1H, brs,> N H ), 3.78 (2H, t, J = 6.0Hz, -NH-C H ₂ -CH ₂ ), 3.48 (2H, t, J = 6.0Hz, -CH ₂ -C H ₂ -OH), 2.25 (1H, brs, -O H )
¹³ C-NMR (100 MHz, CDCl ₃ ): δ (ppm)
196.4 (CH ₃ - C = O), 160.6 (-NH- C = O), 61.2 ( -C H ₂ -OH), 42.1 (-NH- C H ₂ ), 24.5 ( C H ₃ -C = O)
IR (KBr) (cm ^-1 )
3403, 2941, 2885, 2528, 2312, 1724, 1668, 1535, 1460, 1414, 1360, 1265, 1219, 1178, 1128, 1068, 1057, 1018, 966, 939, 903, 872, 804, 771, 700,606, 536, 513, 486, 407
A ¹ H-NMR measurement chart is shown in FIG. 1, a ¹³ C-NMR measurement chart is shown in FIG. 2, and an IR measurement chart is shown in FIG.

Example 2 [Production of N-laurylpyruvic acid amide (1-b)]
The reaction formula in this production is shown below.

In a 500 mL four-necked flask, 81.81 g (0.705 mol) of ethyl pyruvate (3-a) and 152.38 g (1.409 mol) of benzyl alcohol (4-a) were added and stirred to 0 ° C. Cooled down. 100.00 g (0.705 mol) of boron trifluoride ether complex was added dropwise to the reaction solution over 15 minutes. The reaction temperature after completion of the dropwise addition was 10 ° C. Then, it heated up to room temperature and stirred at room temperature for 1 hour. The reaction solution was dropped into 2 L of a saturated sodium hydrogen carbonate solution over 2 hours, and the separated upper layer was collected. The upper layer (222.80 g) was subjected to simple distillation (column top 68 ° C., column bottom 120 ° C., 36 Pa) to remove the low boiling portion, and as a brown oil remaining in the flask, the benzyl acetal compound (5-a) 67.40 g (purity 90.3%) was obtained.
To a 500 mL four-necked flask, 67.00 g (0.192 mol) of the obtained benzyl acetal (5-a), ethanol (96 mL), 39.24 g (0.212 mol) of laurylamine (2-b) were added. The mixture was stirred at room temperature for 5 minutes. 39.30 g (0.114 mol) of a 20% sodium ethoxide ethanol solution was added dropwise over 5 minutes, followed by stirring at room temperature for 85 hours. Ion exchange water (500 mL) and hexane (100 mL) were added, and the upper layer was washed with a pH 6.86 buffer until the aqueous layer became neutral. The upper organic solvent was removed under reduced pressure to obtain 74.10 g of a brown oily crude product. Recrystallization using a hexane solvent gave 39.30 g (purity 100.0%) of an amide compound (6-b) as a white crystal.
To a 500 mL hydrogenation flask, 24.00 g (0.053 mol) of the amide compound (6-b), 3.49 g of 4.5% Pd-0.5% Pt / C and ethanol (176 mL) were added, and a hydrogen atmosphere (0 The mixture was stirred at room temperature for 36.5 hours. Ion exchange water (50 mL) was added and the catalyst was filtered. The solvent was removed under reduced pressure, and the resulting white crystals were purified by silica gel column chromatography (eluent; hexane: ethyl acetate = volume ratio 4: 1) to give N-laurylpyruvic acid amide (1-b) 9 .61 g was obtained.

The measurement results of ¹ H-NMR, ¹³ C-NMR and IR of the obtained N-laurylpyruvic acid amide (1-b) are shown below.
¹ H-NMR (400 MHz, CDCl ₃ ): δ (ppm)
6.92 (1H, brs,> N H ), 3.27 (2H, q, J = 6.6Hz, -NH-C H ₂ -CH ₂ ), 2.47 (3H, s, C H ₃ -C = O), 1.53 ( 2H, quint., -NH-CH ₂ -C H _2- ), 1.22-1.34 (18H, m, -NH-CH ₂ -CH _2- (C ₉ H ₁₈ ) -CH ₃ ), 0.88 (3H, t , J = 7.2Hz, C H ₃ -C = O)
¹³ C-NMR (100 MHz, CDCl ₃ ): δ (ppm)
197.3 (CH ₃ - C = O), 160.2 (-NH- C = O), 39.8 (-NH- C H _2- ), 32.3, 30.0, 30.0, 29.9, 29.9, 29.9, 29.7, 29.6, 27.3, 24.9 ( C H ₃ -C = O), 23.1, 14.6 (-CH ₂ - C H ₃ )
IR (NaCl) (cm ^-1 )
3336, 2954, 2920, 2850, 1724, 1660, 1523, 1468, 1406, 1360, 1296, 1273, 1255, 1230, 1200, 1173, 1055, 1012, 968, 889, 868, 760, 723, 650, 617, 505, 455, 420
4 shows a ¹ H-NMR measurement chart, FIG. 5 shows a ¹³ C-NMR measurement chart, and FIG. 6 shows an IR measurement chart.

Example 3
Deodorant 1 was prepared by dissolving 2 g of N-2-hydroxyethylpyruvic acid amide (1-a) produced in Example 1 in 38 g of water.
Example 4
Deodorant 2 was prepared by dissolving 2 g of N-laurylpyruvic acid amide (1-b) produced in Example 2 in 38 g of water.

Test Example 1 (Deodorizing effect on ammonia)
A filter paper having a length of 7 cm and a width of 0.5 cm was separately impregnated with 250 mg of the deodorizers 1 and 2 obtained in Examples 3 and 4, and 50 mg of a 1% aqueous ammonia solution was subsequently added to the same filter paper. A filter paper was placed in a 3 L beaker, wrapped and left for 20 minutes, and then the sensory evaluation of the odor filled in the beaker was performed.
As blank 1, filter paper not impregnated with deodorant was used, as blank 2, filter paper impregnated with 250 mg of water was used instead of deodorant, and as blank 3, 259 mg of ethanol was impregnated instead of deodorant. A similar test was conducted using filter paper.
The sensory evaluation was performed in four stages of 0 to 3, with the initial ammonia odor before being left as 3 and 0 when no ammonia odor was felt. Sensory evaluation was performed by five panelists, and the average value was obtained. The results are shown in Table 1.

表1の結果から、実施例３及び４の消臭剤１及び２は、ブランク１〜３に比べて、アンモニアに対する消臭効果が優れていることが分かる。

From the results in Table 1, it can be seen that the deodorizers 1 and 2 of Examples 3 and 4 are superior in deodorizing effect on ammonia as compared with the blanks 1 to 3.

Test Example 2 (Deodorizing effect on mercaptans)
Sensory evaluation was performed in the same manner as in Test Example 1 except that 150 mg of a propylene glycol solution of 0.0002% methyl mercaptan was used instead of 50 mg of 1% aqueous ammonia. The results are shown in Table 2.

  From the results of Table 2, it can be seen that the deodorizers 1 and 2 of Examples 3 and 4 are superior in deodorizing effect on mercaptans as compared to the blanks 1 to 3.

Test Example 3 (Deodorizing effect on pyridine)
Sensory evaluation was performed in the same manner as in Test Example 1 except that 20 mg of 0.05% aqueous pyridine solution was used instead of 50 mg of 1% aqueous ammonia solution. The results are shown in Table 3.

表３の結果から、実施例３及び４の消臭剤１及び２は、ブランク１〜３に比べて、ピリジンに対する消臭効果が優れていることが分かる。
表１〜３で示された結果より、実施例３及び４の消臭剤１及び２は、アミン類、メルカプタン類及びピリジンの全てに対して消臭効果を有するものであることが分かる。

From the results in Table 3, it can be seen that the deodorizers 1 and 2 of Examples 3 and 4 are superior in the deodorizing effect on pyridine as compared with the blanks 1 to 3.
From the results shown in Tables 1 to 3, it can be seen that the deodorants 1 and 2 of Examples 3 and 4 have a deodorizing effect on all amines, mercaptans and pyridine.

Test Example 4 (Stability test of ethyl pyruvate and N-2-hydroxyethyl pyruvate in aqueous solution)
An aqueous solution in which 0.1 g of ethyl pyruvate, 0.1 g of ethanol, and 99.8 g of ion-exchanged water are mixed is used as Sample 1, and an aqueous solution in which 0.1 g of N-2-hydroxyethylpyruvic acid amide and 99.9 g of ion-exchanged water are mixed. The sample was stirred at 25 ° C., and the residual rates of ethyl pyruvate and N-2-hydroxyethylpyruvic amide were determined by gas chromatography over time. The results are shown in Table 4.

表４の結果より、Ｎ−２−ヒドロキシエチルピルビン酸アミドは、水溶液中で安定であることが分かる。

From the results in Table 4, it can be seen that N-2-hydroxyethylpyruvic acid amide is stable in an aqueous solution.

2 is a ¹ H-NMR measurement chart of N-2-hydroxyethylpyruvic acid amide obtained in Example 1. FIG. 3 is a ¹³ C-NMR measurement chart of N-2-hydroxyethylpyruvic acid amide obtained in Example 1. FIG. 2 is an IR measurement chart of N-2-hydroxyethylpyruvic acid amide obtained in Example 1. FIG. 2 is a ¹ H-NMR measurement chart of N-laurylpyruvic acid amide obtained in Example 2. FIG. 3 is a ¹³ C-NMR measurement chart of N-laurylpyruvic acid amide obtained in Example 2. FIG. 3 is an IR measurement chart of N-laurylpyruvic amide obtained in Example 2. FIG.

Claims (4)

General formula (1)

(Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkenyl group or a hydroxyalkyl group, and may be bonded to each other to form a ring structure). Pyruvate amides. The pyruvate amides according to claim 1, wherein in the general formula (1), one of R ¹ and R ² is a hydrogen atom. Under acidic conditions, the lower alkyl ester of pyruvic acid is reacted with alcohols to acetalize the carbonyl group at the 2-position of the lower alkyl ester of pyruvic acid, then under general conditions (2)

(Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkenyl group or a hydroxyalkyl group, and may be bonded to each other to form a ring structure). To obtain an acid amide compound, followed by hydrogenolysis under a hydrogen atmosphere to deacetalize the general formula (1)

(Wherein R ¹ and R ² are the same as described above).   A deodorant containing the pyruvate amides according to claim 1 or 2.

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