JP3281916B2 - Method for producing acetal compound and catalyst for the production reaction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an acetal compound and a catalyst for producing the same.

[0002]

2. Description of the Related Art Conventionally, 1,1-di-alkoxy-2-oxo compounds having an acetal group at the α-position of a ketone group have been
Despite expectations for a wide range of applications,
Due to the difficulty in synthesis, its synthesis method has not been known so far.

[0003]

Accordingly, the present invention provides
An object of the present invention is to provide a method for producing an acetal compound having an acetal group at the α-position of a ketone group, and a catalyst for producing the acetal compound.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on the Pummeler reaction between a methylsulfinylmethyl ketone or a methylthioacetal compound and a hydroxy compound. The inventors have found that compounds can be synthesized, and have accomplished the present invention based on this finding. That is, the present invention is characterized in that is reacted in the presence of (1) methylsulfinyl methyl ketone and hydroxy compound represented by (II) (R 2 ^OH) and the silver salt or we chosen solid acid A method for producing an acetal compound represented by the formula (I)
Formula (I).

[0005]

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(Wherein R ¹ and R ² represent an aliphatic group, an aromatic group or a heterocyclic group). Formula (II)

[0007]

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(Wherein, R ¹ has the same meaning as described above; Me is methyl.) (2) A methylthioacetal compound represented by the formula (III) and a hydroxy compound (R ² OH) are Salt and copper salt
Method for producing a pressurized et chosen to react in the presence of a solid acid, wherein (1) acetal compound of formula (I) according to claim (hereinafter sometimes referred to as the second production method), Formula (III)

[0009]

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(Wherein R ¹ , R ² and Me have the same meaning as described above,
R ³ represents a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group. ) (3) (1) used in the reaction in the process according to item, acetal synthesis catalyst, characterized by comprising a silver salt or et solid acids selected, and (4) (2) The method according to claim used in the reaction in, there is provided an acetal synthesis catalyst, characterized in that it consists of a solid acid selected silver salt and a copper salt or al.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, the compound represented by the formula (I) includes a methylsulfinyl methyl ketone represented by the formula (II) or a methylthioacetal compound represented by the formula (III) and the hydroxy compound (R ² OH). Can be synthesized by reacting in the presence of a specific catalyst. The methylsulfinyl methyl ketone represented by the formula (II) is a β-ketosulfoxide compound having various types of chemical structures from aliphatic to aromatic, heterocyclic and alicyclic, and is prepared by a usual method. For example, it can be easily synthesized by reacting a carboxylic acid ester with dimsyl sodium. Similarly, the methylthioacetal compound represented by the formula (III) can be similarly prepared by a usual method. For example, when R ³ is a hydrogen atom, the β-ketosulfoxide compound represented by the formula (II) can be added to a mineral such as hydrochloric acid. It can be synthesized by reacting an aqueous acid solution, and R ³ is a group other than a hydrogen atom (an aliphatic group,
If an aromatic group or a heterocyclic group) can be synthesized by reacting a represented by β- Ketosuruhokishido compound Formula (II), the corresponding hydroxy compounds with R ³ and (R 3 ^OH) .

In the compounds represented by the formulas (I) to (III) and the hydroxy compound (R ² OH), R ¹ and R ² represent an aliphatic group, an aromatic group or a heterocyclic group. Aliphatic groups include linear and cyclic ones. Examples of the chain aliphatic group include an alkyl group having 1 to 16, preferably 1 to 8 carbon atoms. Examples of the cyclic aliphatic group include a cycloalkyl group having 3 to 14, preferably 3 to 10 carbon atoms. Examples of the aromatic group include an aryl group having 6 to 14 carbon atoms, preferably 6 to 10 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms, preferably 7 to 10 carbon atoms. Examples of the heterocyclic group include a 5- to 10-membered, preferably 5- to 6-membered heterocyclic group having an oxygen, nitrogen, sulfur atom or the like as a hetero atom.

Specific examples of R ¹ and R ² include, for example, alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, heptadecyl, aryl groups such as phenyl and naphthyl, aralkyl groups such as benzyl and phenylethyl, and cyclopentyl. And cycloalkyl groups such as cyclohexyl and decahydronaphthyl; heterocyclic groups such as furyl, pyridyl, thienyl, quinolyl, piperidyl and pyranyl and substituted derivatives thereof. R ¹ is preferably any of the above groups unless it has a sterically hindered group. R ² is preferably an aliphatic group, and particularly preferably propyl or butyl.

In the present invention, the hydroxy compound (R ² OH) is preferably an aliphatic alcohol,
For example, in addition to primary alcohols such as methanol, ethanol, hexanol and hexadecanol, secondary alcohols such as 2-propanol and 2-butanol can be used, and alicyclic alcohols such as cyclohexanol and phenol And the like.

The above-mentioned groups represented by R ¹ and R ² may further have a substituent. Examples of such a substituent include an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group and a sulfonyl group. , Ester group, nitro group,
Examples include a carboxyl group and a cyano group. In the compound represented by the formula (III), R ³ represents a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group, and the aliphatic group, the aromatic group and the heterocyclic group are represented by R ¹ And R
^It has the same meaning as the aliphatic group, aromatic group and heterocyclic group in ² . R ³ is preferably an aliphatic group, more preferably ethyl, propyl, butyl, and hexyl, and particularly preferably ethyl and propyl.

The catalyst used in the reaction of the first and second production methods of the present invention has a property as a solid acid, and has a silver salt (for example, silver sulfate (Ag ₂ SO ₄ );
Silver nitrate (AgNO ₃ ), silver carbonate (Ag ₂ CO ₃ ), copper salt (anhydrous cupric chloride (CuCl ₂ ), cupric chloride dihydrate (CuCl ₂ .2H ₂ O), copper sulfate (Cu
SO _4), cupric nitrate _{(Cu (NO 3) 2)} , etc. cupric carbonate (CuCO ₃₎₎ (provided that is intended is selected) or al is not used in the first production method, a commercially available product You may use it as it is. In the first production method of the present invention, the catalyst is preferably a silver salt, more preferably silver sulfate or silver nitrate, and particularly preferably silver sulfate. In the second production method, the catalyst is preferably a silver salt or a copper salt, more preferably a copper salt, and particularly preferably anhydrous cupric chloride. The amount of the catalyst of the present invention can be appropriately determined, and is usually in a weight ratio to the methylsulfinyl methyl ketone represented by the formula (II) or the methylthioacetal compound 1 represented by the formula (III). 0.1 to 0.7.

In the method of the present invention, this catalyst is added together with the hydroxy compound and the methylsulfinyl methyl ketone represented by the formula (II) or the methylthioacetal compound represented by the formula (III), and reacted by heating and stirring. The reaction molar ratio between the methylsulfinyl methyl ketone represented by the formula (II) or the methylthioacetal compound represented by the formula (III) and the hydroxy compound is not particularly limited, but is preferably in the range of 1: 4 to 1:10. preferable. The reaction temperature is preferably 40 to 120 ° C, more preferably 60 to 120 ° C.
° C or higher, and the reaction time is not particularly limited, but is usually 1 to
25 hours. The reaction may be carried out in a solvent or in the absence of a solvent, but is preferably carried out in a solvent. In some cases, the hydroxy compound itself is used as a solvent by using an excess thereof, or a compound other than the hydroxy compound is used as the solvent. Specific examples of the solvent other than the hydroxy compound include solvents such as dichloromethane, acetonitrile, dioxane, nitromethane, and chloroform. After the reaction, the target acetal compound represented by the formula (I) can be obtained by removing the catalyst by a simple filtration operation and removing the solvent from the obtained filtrate. The reaction of the present invention belongs to the Pummeler rearrangement reaction.

[0018]

EXAMPLES Next, the present invention will be described in more detail based on Examples.
explain. Example 1 Methylsulfinyl methyl ketone (II) (R¹= P-
(OMe) phenyl) 0.098 g, silver sulfate 0.020
g, propanol (R²OH, R²= N-C₃H ₇) 5
The ml mixture was stirred at 90 ° C. for 22 hours. After the reaction,
The catalyst was removed by filtration, and the solvent was removed from the filtrate under reduced pressure.
The residue is purified by chromatography on silica gel.
And 0.118 g (96%) of pure oil as a colorless oil
Stylish 1,1-dialkoxy-2-oxo compound (I)
(R¹= P- (OMe) phenyl, R²= N-C
₃H₇) Got. Analytical values such as NMR of the obtained compound
It is shown below. Rf (SiO₂/ Benzene): 0.36 M⁺(M / z): 266 IR (Neat): 1684 (νC = O), 1066c
m^-1(ΝC-O) NMR (CDCl₃): Δ¹H 5.20s, δ¹³C
 104.46 (CH (1))

Comparative Example 1 The operation was carried out in exactly the same manner as in Example 1 except that no silver sulfate was used. As a result, no reaction proceeded.

Example 2 1-Hydroxy-1-methylthio-2-oxo compound (III) (R ¹ = p- (OMe) phenyl, R ³ = H)
0.102 g, anhydrous cupric chloride 0.025 g, propanol _{^{(R 2 OH, R 2 =}} n-C 3 H 7) a mixture of 5 ml, and stirred for 2 hours at 90 ° C.. After the reaction, the catalyst was removed by filtration, and the solvent was removed from the filtrate under reduced pressure. The residue was purified by chromatography on silica gel and 0.126 g (96%) of pure 1,1-dialkoxy-2-oxo compound (I) (R ¹ = p- (OM)
e) ^phenyl, to obtain a _{R 2 = n-C 3 H} 7).

Comparative Example 2 The operation was carried out in exactly the same manner as in Example 2 except that anhydrous cupric chloride was not used, and the reaction did not proceed at all.

Example 3 1-ethoxy-1-methylthio-2-oxo compound (II
I) (R ¹ = phenyl, R ³ = C ₂ H ₅ ) 0.108
g, anhydrous cupric chloride 0.030 g, and propanol (R ²
OH, R ² = nC ₃ H ₇ )
For 2 hours. After the reaction, the catalyst was removed by filtration, and the solvent was removed from the filtrate under reduced pressure. The residue is purified by chromatography on silica gel and 0.110 g (91%) of pure 1,1-dialkoxy-2-oxo compound (I) (R ¹ = phenyl, R ² = n) as a colorless oil.
-C ₃ H ₇₎ was obtained.

Comparative Example 3 The operation was carried out in exactly the same manner as in Example 3 except that anhydrous cupric chloride was not used, and the reaction did not proceed at all.

[0024]

As described above, according to the production method of the present invention, an acetal compound having an acetal group at the α-position of a ketone can be obtained with a high yield. Such compounds are:
Since it has a specific reactivity derived from the oxygen-containing polar functional group, as a reaction material for synthesizing a functional substance, a hydrophobic group is introduced by a reaction of a carbonyl group of the compound, and an acetal group is introduced. It can be a hydrophilic group and can be used as a raw material for surfactants and heavy metal collectors. Further, if the catalyst of the present invention is used, there is no problem of waste liquid treatment,
The target acetal compound can be produced by performing the Punmeler reaction cleanly. Further, this catalyst has an excellent effect that the catalytic activity is large and post-treatment after the reaction is easy.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ identification code FI // C07B 61/00 300 C07B 61/00 300 (58) Investigated field (Int. Cl. ⁷ , DB name) C07C 45/64 C07C 45/84 C07C 49/175 C07C 49/255 C07C 49/35 C07C 49/517 C07C 49/577 C07C 49/753 C07C 41/50 C07C 43/30-43/315 C07B 61/00 300 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. A method according to claim 1, wherein the methylsulfinyl methyl ketone represented by the formula (II) and a hydroxy compound (R ² OH) are
Production method represented by acetal compound with formula (I) which comprises reacting in the presence of a salt or we chosen a solid acid. Formula (I) (In the formula, R ¹ and R ² represent an aliphatic group, an aromatic group or a heterocyclic group.) Formula (II) (In the formula, R ¹ has the same meaning as described above. Me is methyl.) 2. A method according to claim 1, wherein the methylthioacetal compound represented by the formula (III) and the hydroxy compound (R ² OH) are
And method for producing an acetal compound represented by the formula (I) according to claim 1, characterized in that the reaction in the presence of a copper salt or we chosen a solid acid. Formula (III) (Wherein, R ¹ , R ² and Me have the same meaning as described above,
R ³ represents a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group. ) 3. A process according to claim 1 used in the reaction in the process according to the catalyst for the acetal synthesis characterized by comprising the silver salt or et solid acids selected. 4. The method of claim 2 used in the reaction in the process according to silver salt and a copper salt or found to consist of a solid acid catalyst for acetal synthesis, characterized in that selected.