JP2005179324A - METHOD FOR STORING omega-MERCAPTOALKYLPYRIDINES - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of stably storing ω-mercaptoalkylpyridines or their solutions in a container. <P>SOLUTION: The method of storing ω-mercaptoalkylpyridines represented by formula (I) [wherein n' is an integer of 0-2, and when n' is 0, a group -(CH<SB>2</SB>)<SB>n'</SB>- is a single bond; and q' is an integer of 0-2] or their solutions in a container comprises adjusting the oxygen concentration of the gas phase part in the container to ≤1 (V/V)%. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for storing ω-mercaptoalkylpyridines or a solution thereof.

Ω-mercaptoalkylpyridines such as 2- (2-mercaptoethyl) pyridine and 4- (2-mercaptoethyl) pyridine are additives for chelating catalysts used in the production of bisphenol A, intermediates for medicines and agricultural chemicals, etc. As a useful compound.
Conventionally, as a method for producing ω-mercaptoalkylpyridines, for example, a method for producing 2- (2-mercaptoethyl) pyridine by reacting 2-vinylpyridine with hydrogen sulfide (Non-Patent Document 1) is known. And Non-Patent Document 2).

P.S.K.Chia et al., Aust. J. Chem., 19, 1835 (1966)

R.B.Thompson et al., Industrial and Engineering Chemistry, 44, 1659 (1952)

  When stored in contact with air, the ω-mercaptoalkylpyridines obtained by the method described in the above-mentioned non-patent document have the formula (IV)

[Wherein n ′ represents an integer of 0 to 2, and when n ′ is 0, it represents a single bond. q ′ represents an integer of 0 to 2. ]
As a by-product, the compound represented by the formula has a problem that the purity of ω-mercaptoalkylpyridines is lowered. In order to solve this problem, the ω-mercaptoalkylpyridines obtained by the above method are reacted with a mineral acid quickly to obtain an ω-mercaptoalkylpyridines mineral acid salt, or obtained by the above method. In addition, it was necessary to quickly use ω-mercaptoalkylpyridines as an additive for a chelate catalyst for producing bisphenol A.
However, ω-mercaptoalkylpyridines are usually stored before being used as an additive for a chelate catalyst for producing bisphenol A. And there was a problem that the by-product amount of the compound (IV) increased during storage, and the purity of ω-mercaptoalkylpyridines was lowered.

  An object of the present invention is to provide a method for preserving ω-mercaptoalkylpyridines or solutions thereof in which compound (IV) or the like is not by-produced even when ω-mercaptoalkylpyridines (I) are stored for a long period of time. .

  That is, the present invention provides the following formula (I)

［式中、ｎ’は０〜２の整数を表し、ｎ’が０であるときは、単結合を表す。ｑ’は０〜２の整数を表す。］
で表されるω−メルカプトアルキルピリジン類又はその溶液を容器に保存する方法であって、該容器内の気相部の酸素濃度を１％（Ｖ／Ｖ）以下に調節することを特徴とするω−メルカプトアルキルピリジン類又はその溶液の保存方法を提供するものである。

[Wherein n ′ represents an integer of 0 to 2, and when n ′ is 0, it represents a single bond. q ′ represents an integer of 0 to 2. ]
Is stored in a container, and the oxygen concentration in the gas phase in the container is adjusted to 1% (V / V) or less. The present invention provides a method for preserving ω-mercaptoalkylpyridines or solutions thereof.

According to the present invention, ω-mercaptoalkylpyridines (I) or a solution thereof can be stably stored for a long period of time.
Moreover, according to this invention, by-products, such as a compound shown by said Formula (IV), can be suppressed during the preservation | save of the said omega-mercaptoalkylpyridine (I) or its solution.

Hereinafter, the present invention will be described in detail.
Examples of the ω-mercaptoalkylpyridines (I) in the preservation method of the present invention include, for example, the following formula (III)

[Wherein n ′ represents an integer of 0 to 2, and when n ′ is 0, it represents a single bond. q ′ represents an integer of 0 to 2. ]
And those obtained by reacting pyridines represented by the formula (II) with hydrogen sulfide in the presence of a tertiary amine different from the above pyridines.

Examples of the ω-mercaptoalkylpyridines obtained by the above reaction include the following.
(A) a reaction solution obtained by reacting in the presence or absence of a hydrophobic organic solvent,
(B) a hydrophobic organic solvent solution of ω-mercaptoalkylpyridines obtained by washing a reaction solution obtained by reacting in the absence of a hydrophobic organic solvent with water in the presence of a hydrophobic organic solvent;
(C) ω-mercaptoalkylpyridines obtained by distillation or rectification of the reaction solution of (a) or the solution of (b) above,
(D) a reaction product containing ω-mercaptoalkylpyridines obtained by further decomposing a reaction solution obtained by the reaction of pyridines (III) and thiourea with an alkali or the like;
(E) ω-mercaptoalkylpyridines obtained by distilling the reaction product of (d) above

When using hydrogen sulfide, in order to carry out the reaction efficiently, the reaction vessel or reaction vessel may be sealed or pressurized as necessary.
The amount of hydrogen sulfide used is usually in the range of 1 to 30 moles per mole of pyridines (III). When a sealed container is used as a reaction container, the amount of hydrogen sulfide used is usually in the range of 1 to 10 moles per mole of pyridines (III).
The hydrogen sulfide used for producing the ω-mercaptoalkylpyridines (I) in the preservation method of the present invention may be used in the form of a solution dissolved in an organic solvent, water or the like, or hydrogen sulfide gas may be used. Good. Examples of the organic solvent for dissolving hydrogen sulfide include aromatic hydrocarbon solvents and aliphatic hydrocarbon solvents. The dissolved state of hydrogen sulfide in the organic solvent may be a saturated concentration or an unsaturated concentration.

In the preservation method of the present invention, a reaction containing ω-mercaptoalkylpyridines (I) is carried out by reacting pyridines (III) and hydrogen sulfide in the presence of a tertiary amine different from the pyridines. A liquid is obtained.
Specifically, the above reaction is performed by the following method or the like.
(A) A method of introducing hydrogen sulfide into a mixture containing a tertiary amine, pyridines (III) and, if necessary, a reaction solvent;
(A) A method of introducing pyridines (III) after introducing hydrogen sulfide into a mixture of a tertiary amine and a reaction solvent or into a tertiary amine;
(C) A method in which a tertiary amine is introduced into hydrogen sulfide in a reaction vessel or reaction vessel, and then pyridines (III) are introduced;
(D) A method in which a tertiary amine and pyridines (III) are simultaneously introduced into hydrogen sulfide in a reaction vessel or reaction vessel;
(E) A method in which a tertiary amine, pyridines (III) and hydrogen sulfide are simultaneously introduced into a reaction vessel or reaction vessel.

  In the preservation method of the present invention, a method of introducing pyridines (III) into a reaction vessel or reaction vessel in which hydrogen sulfide is previously present, as in the reaction methods (c) and (d) above, is represented by the following formula (V):

（式中、ｎ’及びｑ’はそれぞれ前記の定義である。）

(In the formula, n ′ and q ′ are as defined above.)

The method (c) is particularly preferred because it tends to suppress the amount of by-products such as sulfides represented by formula (1).
The gauge pressure after hydrogen sulfide introduction (differential pressure with respect to atmospheric pressure) is preferably 0.1 to 1.5 MPa, more preferably 0.2 to 1.0 MPa. The form of hydrogen sulfide in the reaction vessel may be a gas state or a liquid state. Further, the pressure may be adjusted using an inert gas such as nitrogen or helium during pressurization. Furthermore, unreacted hydrogen sulfide remaining after the reaction may be transferred to a separately installed reaction vessel and reused for the next reaction.

  The temperature of the reaction in the storage method of the present invention is usually in the range of −40 to 100 ° C., preferably in the range of −30 to 60 ° C. A reaction temperature of −40 ° C. or higher is preferable because the reaction rate tends to be improved, and a temperature of 100 ° C. or lower is preferable in that the amount of by-products such as sulfides represented by the formula (V) is suppressed. .

  The reaction time in the preservation method of the present invention varies depending on the pyridines (III), the amount of tertiary amine and hydrogen sulfide different from the pyridines, the introduction method of these raw material compounds, the reaction temperature, and the like. However, it is usually in the range of 0.1 to 20 hours.

Among the pyridines (III) used in producing the ω-mercaptoalkylpyridines (I) in the preservation method of the present invention, pyridines having n ′ of 0 are preferable, and pyridines having n ′ and q ′ of 0 are preferred. Are more preferable, and 2-vinylpyridine or 4-vinylpyridine is particularly preferable.
When the pyridine (III) contains a polymerization inhibitor such as hydroquinone or catechol, it is preferable to remove the polymerization inhibitor in the pyridine using a means such as distillation before use in the reaction.

The amount of the tertiary amine used in producing the ω-mercaptoalkylpyridines (I) in the preservation method of the present invention may be 0.005 mol or more per mol of the pyridines (III).
The tertiary amine preferably used is one or more amines selected from the group consisting of the following (A) to (C).

(A): Tertiary amine represented by the following formula (a)

[R ^{21 to} R ²³ in Formula (a) are each independently a chain alkyl group having 1 to 8 carbon atoms, a cyclic alkyl group having 4 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms. Represent. The chain alkyl group, the cyclic alkyl group, and the hydrogen atom in the aromatic hydrocarbon group include an amino group, an N-alkylamino group having 1 to 8 carbon atoms, and an N, N-dialkylamino group having 1 to 8 carbon atoms. It may be substituted with one or more groups selected from a group and a hydroxyl group. ]

(B): An alicyclic tertiary amine represented by the following formula (b)

[R ²⁴ in Formula (b) represents a chain alkyl group having 1 to 8 carbon atoms, a cyclic alkyl group having 4 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and the chain alkyl group , The hydrogen atom in the cyclic alkyl group and the aromatic hydrocarbon group is an amino group, an N-alkylamino group (wherein the alkyl has 1 to 8 carbon atoms), N, N-dialkyl, respectively. An amino group (provided that each alkyl independently has 1 to 8 carbon atoms) or a hydroxyl group may be substituted. In addition, a part of —CH ₂ — in the heterocyclic ring in the formula (b) may be substituted with —NH— or —O—. m represents an integer of 0 to 8. ]

(C): nitrogen-containing aromatic heterocyclic compound [in the nitrogen-containing aromatic heterocyclic compound, an alkyl group having 1 to 8 carbon atoms may be bonded to a carbon atom constituting the heterocyclic ring; The hydrogen atom in the group is an amino group, an N-alkylamino group (wherein the alkyl has 1 to 8 carbon atoms), or an N, N-dialkylamino group (wherein each alkyl has 1 carbon number independently) -8) or may be substituted with a hydroxyl group. ]

As said chain | strand-shaped alkyl group, C1-C8 linear or branched alkyl groups, such as a methyl group, an ethyl group, and a butyl group, are mentioned, for example.
As said cyclic alkyl group, C4-C12 cyclic alkyl groups, such as a cyclopentyl group and a cyclohexyl group, are mentioned, for example.
Moreover, as an aromatic hydrocarbon group, C6-C12 aromatic hydrocarbon groups, such as a phenyl group and a benzyl group, are mentioned, for example.

  Examples of the amine (A) include a tertiary amine having a nitrogen atom bonded to three alkyl groups and a tertiary amine having a nitrogen atom bonded to an aromatic hydrocarbon group.

  Examples of the tertiary amine having a nitrogen atom bonded to the three alkyl groups include amines represented by the following formulas (1) to (6).

[R ^{3 to} R ⁵ in Formula (1) each independently represent a chain alkyl group having 1 to 8 carbon atoms or a cyclic alkyl group having 4 to 12 carbon atoms. ]
Specific examples of the tertiary amine represented by the formula (1) include trimethylamine and triethylamine.

[R ^{6 to} R ⁹ in Formula (2) each independently represent a chain alkyl group having 1 to 8 carbon atoms or a cyclic alkyl group having 4 to 12 carbon atoms, and p represents an integer of 1 to 3. ]
Specific examples of the tertiary amine represented by the formula (2) include N, N, N ′, N′-tetramethyldiaminomethane, N, N, N ′, N′-tetramethylethylenediamine and N, N. , N ′, N′-tetramethyl-1,3-propanediamine and the like.

[R ^{10 to} R ¹² in Formulas (3) and (4) each independently represents a chain alkyl group having 1 to 8 carbon atoms or a cyclic alkyl group having 4 to 12 carbon atoms. q and r each independently represent an integer of 1 to 4. ]
Examples of the tertiary amine represented by the formula (3) include N, N-diethylethanolamine. Moreover, N-methyldiethanolamine etc. are illustrated as a tertiary amine represented by Formula (4).

  Examples of the tertiary amine having a nitrogen atom bonded to an aromatic hydrocarbon group include amines represented by formulas (5) and (6).

［式（５）及び（６）におけるＲ^1３〜Ｒ^1５は、それぞれ独立に、炭素数１〜８の鎖状アルキル基又は炭素数４〜１２の環状アルキル基を表す。また、φ₁〜φ_３は、それぞれ独立に芳香族炭化水素基を表す。］

[Equation (5) and R ¹³ to R ¹⁵ in (6) each independently represent a linear alkyl group or a cyclic alkyl group having 4 to 12 carbon atoms having 1 to 8 carbon atoms. Φ _{1 to} φ ₃ each independently represents an aromatic hydrocarbon group. ]

  Examples of (B) alicyclic tertiary amines include bis (aminopropyl) piperazine, N-methylpiperazine, 1- (2-aminoethyl) piperazine, (hydroxyethyl) piperazine, N-methylpiperidine, N Examples include amines such as -methylmorpholine, N-ethylmorpholine, and N- (3-aminopropyl) morpholine.

  Examples of the nitrogen-containing aromatic heterocyclic compound (C) include amines such as pyridine, α-picoline, γ-picoline, lutidine and 4-piperidinopyridine.

As the tertiary amine used in producing the ω-mercaptoalkylpyridines (I) in the preservation method of the present invention, a mixture of two or more kinds of tertiary amines may be used.
As the tertiary amine, from the viewpoint of the yield of the ω-mercaptoalkylpyridines (I), the tertiary amines of the above (A) and (B) are preferable, and the formulas (1) and (A) of (A) are preferable. 2), tertiary amines represented by (5) and (6) and one or more tertiary amines selected from the group consisting of (B) alicyclic tertiary amines are more preferred. The tertiary amines represented by 1) and (2) are particularly preferred.

The ω-mercaptoalkylpyridines (I) obtained by the above method in the storage method of the present invention can be stored by adjusting the oxygen concentration in the gas phase in the container to 1% (V / V) or less. The ω-mercaptoalkylpyridines (I) after the storage are usually neutralized with a hydrophobic organic solvent solution of the ω-mercaptoalkylpyridines (I) with, for example, a mineral acid or an organic acid, and then the ω-mercaptoalkylpyridines. It can be used as an additive of a chelate catalyst for the production of bisphenol A as an aqueous solution of the class (I) mineral acid salt or organic acid salt.
Examples of the mineral acids include hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid.
Moreover, acetic acid etc. are mentioned as organic acids.

The hydrophobic organic solvent may be added to the reaction solution obtained by the reaction of the pyridines (III) and hydrogen sulfide described above, or may be added as the reaction solvent.
Examples of the hydrophobic organic solvent added to the reaction solution obtained by the reaction of pyridines with hydrogen sulfide include aliphatic ketones having 5 or more carbon atoms (such as methyl isobutyl ketone) and aliphatic hydrocarbons (hexane, heptane, octane). Etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, ethylbenzene, xylene, cymene, etc.).
Examples of the hydrophobic organic solvent added as a reaction solvent include aliphatic hydrocarbons (hexane, heptane, octane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, ethylbenzene, xylene, cymene, etc.) ).
As the hydrophobic organic solvent, a mixture of two or more kinds of solvents described above may be used.

The amount of the hydrophobic organic solvent used is usually in the range of 0.5 to 5 parts by weight, preferably in the range of 1 to 4 parts by weight per part by weight of the reaction solution.
If the amount of the hydrophobic organic solvent used is less than 0.5 times by weight, the liquid separation property at the time of washing with water tends to deteriorate, and the yield of ω-mercaptoalkylpyridines (I) tends to decrease. On the other hand, even if the amount of the hydrophobic organic solvent used exceeds 5 times by weight, the yield of ω-mercaptoalkylpyridines is not improved, which is economically disadvantageous.

  Although washing with water may be performed in an air atmosphere, it is preferably performed in an atmosphere of an inert gas such as nitrogen or argon from the viewpoint of suppressing the amount of by-product of the compound (IV) described above.

  The temperature at the time of washing is usually in the range of 5 to 90 ° C, preferably in the range of 10 to 60 ° C. When the temperature at the time of washing is less than 5 ° C., the yield of ω-mercaptoalkylpyridines (I) tends to be reduced. There is a tendency that the solubility becomes relatively higher than the solubility in water, and the amount of washing water necessary for the removal of the tertiary amine increases.

The amount of water during washing is usually in the range of 0.1 to 2 parts by weight, preferably in the range of 0.1 to 1 part by weight per part by weight of the reaction solution.
When the amount of water at the time of washing exceeds 2 times by weight, the yield of ω-mercaptoalkylpyridines (I) tends to decrease. Moreover, when the amount of water at the time of washing is less than 1 times by weight, the separation property between the hydrophobic organic solvent and water tends to deteriorate.

The number of washings is usually 1 to 10 times, preferably 3 to 5 times, although it varies depending on the amount of tertiary amine different from the above pyridines (III).
When washing with water is not performed, coloring matter in the reaction solution cannot be removed, and when the number of washings increases, the yield of ω-mercaptoalkylpyridines (I) tends to decrease.

  The hydrophobic organic solvent solution of ω-mercaptoalkylpyridines (I) and ω-mercaptoalkylpyridines (I) stored by the method of the present invention has an oxygen concentration of 1% ( When adjusted to V / V) or less, the by-product of the compound (IV) is suppressed, and the ω-mercaptoalkylpyridines (I) can be stably stored for a long period of time.

  When the oxygen concentration in the gas phase in the container for storing the ω-mercaptoalkylpyridines (I) exceeds 1% (V / V), the compound (IV) gradually increases. Moreover, when it preserve | saves by oxygen concentration 21V / V% (in air | atmosphere), the said compound (IV) will increase remarkably and the purity of omega-mercaptoalkylpyridine (I) will fall.

  The storage temperature is preferably in the range of −30 to 60 ° C., more preferably in the range of −20 to 30 ° C. in view of both the by-product amount and practicality of the compound (IV).

  In the storage method of the present invention, the oxygen concentration may be adjusted by venting an inert gas into the storage container to adjust the oxygen concentration in the gas phase in the container, or by using a vacuum pump or the like. The oxygen concentration may be adjusted by reducing the pressure. In addition, when the oxygen concentration is adjusted using an inert gas, the inert gas may be passed through the gas phase portion in the container, or the oxygen concentration may not be contained in the liquid ω-mercaptoalkylpyridines (I). The active gas may be bubbled by bubbling.

Examples of the inert gas include nitrogen, helium, argon, neon, and the like.
The amount of the inert gas when the inert gas is vented may be a gas amount at which the oxygen concentration in the gas phase portion in the storage container is 1 V / V% or less.

  In the storage method of the present invention, it is preferable to increase the storage amount of the ω-mercaptoalkylpyridines (I) so that the volume of the gas phase in the storage container becomes as small as possible.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further in detail, this invention is not limited by these examples.

[Calculation method of yield of 4- (2-mercaptoethyl) pyridine]
The yield of 4- (2-mercaptoethyl) pyridine was determined by the area percentage method using a liquid chromatograph under the following conditions after diluting the solution after completion of the reaction with a mixture of acetonitrile / water.
<Area percentage method>
Column: L-column ODS 4.6 mmφ × 15 cm
Mobile phase: acetonitrile / water containing 2.5 mmol / L 1-pentanesulfonic acid sodium salt Detection: UV 254 nm

Reference example 1
After replacing the inside of the autoclave with hydrogen sulfide, 545 g (16 mol) of hydrogen sulfide was introduced while maintaining the pressure at about 0.5 MPa (gauge pressure 5 kg / cm ² ).
Next, a mixed solution of 420.9 g (4 mol) of 4-vinylpyridine and 18.6 g (0.2 mol) of N, N, N ′, N′-tetramethylethylenediamine was stirred at 5 ° C. over 3 hours. It was dripped. After completion of the dropwise addition, the mixture was stirred at 3 ° C. for 1 hour, and then the pressure in the autoclave was gradually returned to atmospheric pressure to remove excess hydrogen sulfide, and the reaction product containing 4- (2-mercaptoethyl) pyridine 549. 5 g was obtained. As a result of analyzing this reaction product, the purity of 4- (2-mercaptoethyl) pyridine was 94.2%.

Reference example 2
Almost all of the reaction product obtained in Reference Example 1 was transferred to another container under a nitrogen atmosphere, gradually heated to 30 ° C., 1924 g of toluene was added at the same temperature, and 362 g of ion-exchanged water was added. And washed 3 times. The mixture after washing was filtered to obtain 2467 g of toluene solution of 4- (2-mercaptoethyl) pyridine. As a result of analyzing this toluene solution, the purity of 4- (2-mercaptoethyl) pyridine (excluding toluene) was 94.1%.

Example 1
4- (2-mercaptoethyl) obtained in Reference Example 1 in a 55 ml glass storage container (diameter: 33 mm) in a box whose oxygen concentration was adjusted to 1% (V / V) by aeration of nitrogen gas 20 g of the reaction product containing pyridine was added, sealed, and stored at a temperature of 25 ° C. for 14 days. As a result of analyzing the reaction product after storage, the purity of 4- (2-mercaptoethyl) pyridine was 94.1%.

Example 2
The same operation as in Example 1 was performed, except that storage was performed for 30 days. As a result of analyzing the reaction product after storage, the purity of 4- (2-mercaptoethyl) pyridine was 94.0%.

Example 3
The same operation as in Example 1 was performed except that the toluene solution obtained in Reference Example 2 was used. As a result of analyzing the toluene solution after the storage, the purity of 4- (2-mercaptoethyl) pyridine (excluding toluene) was 93.9%.

Comparative Example 1
The same operation as in Example 1 was performed except that the operation was performed in the air without using a box and the glass storage container was opened. As a result of analyzing the reaction product after storage, the purity of 4- (2-mercaptoethyl) pyridine was 93.4%.

Comparative Example 2
The same operation as in Comparative Example 1 was performed except that it was stored for 30 days. As a result of analyzing the reaction product after storage, the purity of 4- (2-mercaptoethyl) pyridine was 91.6%.

Comparative Example 3
The same operation as in Comparative Example 1 was performed except that the toluene solution obtained in Reference Example 2 was used. As a result of analyzing the toluene solution after the storage, the purity of 4- (2-mercaptoethyl) pyridine (excluding toluene) was 93.2%.

* ・ ・ Purity as 4- (2-mercaptoethyl) pyridine

Claims (7)

Formula (I)

[Wherein n ′ represents an integer of 0 to 2, and when n ′ is 0, it represents a single bond. q ′ represents an integer of 0 to 2. ]
The ω-mercaptoalkylpyridine represented by the formula (1) or a solution thereof is stored in a container, wherein the oxygen concentration in the gas phase in the container is adjusted to 1 (V / V)% or less. A method for storing ω-mercaptoalkylpyridines or a solution thereof. The ω-mercaptoalkylpyridines represented by the formula (I) are represented by the following formula (III)

[Wherein n ′ represents an integer of 0 to 2, and when n ′ is 0, it represents a single bond. q ′ represents an integer of 0 to 2. ]
Preservation of ω-mercaptoalkylpyridines or solutions thereof according to claim 1 obtained by reacting pyridines represented by formula (II) with hydrogen sulfide in the presence of a tertiary amine different from the pyridines. Method.   A solution of ω-mercaptoalkylpyridines represented by the formula (I) reacts the pyridines represented by the formula (III) with hydrogen sulfide in the presence of a tertiary amine different from the pyridines. The method for preserving ω-mercaptoalkylpyridines or a solution thereof according to claim 1, which is a solution obtained by washing a reaction solution containing ω-mercaptoalkylpyridines obtained in the above manner with water in the presence of a hydrophobic organic solvent. The ω-mercapto according to claim 2 or 3, wherein the tertiary amine different from the pyridine represented by the formula (III) is at least one amine selected from the group consisting of the following (A) to (C). A method for storing alkylpyridines or a solution thereof.
(A): Tertiary amine represented by the following formula (a)

[R ^{21 to} R ²³ in Formula (a) are each independently a chain alkyl group having 1 to 8 carbon atoms, a cyclic alkyl group having 4 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms. Represent. The chain alkyl group, the cyclic alkyl group, and the hydrogen atom in the aromatic hydrocarbon group include an amino group, an N-alkylamino group having 1 to 8 carbon atoms, and an N, N-dialkylamino group having 1 to 8 carbon atoms. It may be substituted with one or more groups selected from a group and a hydroxyl group. ]
(B): An alicyclic tertiary amine represented by the following formula (b)

[R ²⁴ bonded to the nitrogen atom in the heterocyclic ring in the formula (b) is a chain alkyl group having 1 to 8 carbon atoms, a cyclic alkyl group having 4 to 12 carbon atoms, or an aromatic hydrocarbon having 6 to 12 carbon atoms. A hydrogen atom in the chain alkyl group, the cyclic alkyl group and the aromatic hydrocarbon group is an amino group or an N-alkylamino group (wherein the alkyl has 1 to 8 carbon atoms, respectively). ), An N, N-dialkylamino group (wherein each alkyl independently has 1 to 8 carbon atoms) or a hydroxyl group. In addition, a part of —CH ₂ — in the heterocyclic ring in the formula (b) may be substituted with —NH— or —O—. m represents an integer of 0 to 8. ]
(C): Nitrogen-containing aromatic heterocyclic compound The nitrogen-containing aromatic heterocyclic compound may have an alkyl group having 1 to 8 carbon atoms bonded to a carbon atom constituting the heterocycle, and hydrogen in the alkyl group. The atom is an amino group, an N-alkylamino group (wherein the alkyl has 1 to 8 carbon atoms), an N, N-dialkylamino group having 1 to 8 carbon atoms (where each alkyl is independently a carbon number) Are 1 to 8) or a hydroxyl group.   The pyridine represented by the formula (III) is 4-vinylpyridine and / or 2-vinylpyridine, The method for preserving ω-mercaptoalkylpyridines or a solution thereof according to any one of claims 2 to 4. A tertiary amine different from the pyridines represented by the formula (III) is one or more amines selected from the amine group represented by the following formulas (1), (2), (5) and (6): A method for preserving ω-mercaptoalkylpyridines or a solution thereof according to any one of claims 2 to 5.

[R ^{3 to} R ⁵ in Formula (1) each independently represent a chain alkyl group having 1 to 8 carbon atoms or a cyclic alkyl group having 4 to 12 carbon atoms. ]

[R ^{6 to} R ⁹ in Formula (2) each independently represent a chain alkyl group having 1 to 8 carbon atoms or a cyclic alkyl group having 4 to 12 carbon atoms, and p represents an integer of 1 to 3. ]

[Equation (5) and (6) in R ¹³ to R ¹⁵ each independently represent a linear alkyl group or a cyclic alkyl group having 4 to 12 carbon atoms having 1 to 8 carbon atoms. Φ _{1 to} φ ₃ each independently represents an aromatic hydrocarbon group. ] The method for preserving ω-mercaptoalkylpyridines or a solution thereof according to any one of claims 1 to 6, wherein the hydrophobic organic solvent is one or more solvents selected from the following groups a) to d).
a) Aliphatic hydrocarbons b) Alicyclic hydrocarbons c) Aromatic hydrocarbons d) Aliphatic ketones having 5 or more carbon atoms