阅读说明：本技术 一种制备α-酰氧硫醚衍生物的方法 (Method for preparing alpha-acyloxy thioether derivative ) 是由 李正义 李云剑 戴胜飞 杨科 孙小强 于 2021-01-22 设计创作，主要内容包括：本发明属于精细化工领域,具体涉及一种制备α-酰氧硫醚衍生物的方法。其技术要点如下：将化合物A、羧酸B、羧酸B的钠盐和1-氯甲基-4-氟-1,4-二氮杂双环[2.2.2]辛烷二(四氟硼酸)盐依次加入含有反应溶剂乙腈的封管中反应后蒸出反应溶剂乙腈,得到α-酰氧硫醚衍生物。本发明α-酰氧硫醚衍生物的制备方法,遵循了绿色化学的宗旨,并解决了传统制备α-酰氧硫醚衍生物过程中亚砜的毒性大的等问题,同时本发明采用的催化剂原料种类少、催化剂反应工艺简单、产物提纯方法简便且收率高,具有产业价值。(The invention belongs to the field of fine chemical engineering, and particularly relates to a method for preparing an alpha-acyloxy thioether derivative. The technical points are as follows: and sequentially adding the compound A, the carboxylic acid B, the sodium salt of the carboxylic acid B and 1-chloromethyl-4-fluoro-1, 4-diazabicyclo [2.2.2] octane bis (tetrafluoroborate) into a sealed tube containing a reaction solvent acetonitrile, reacting, and distilling off the reaction solvent acetonitrile to obtain the alpha-acyloxysulfide derivative. The preparation method of the alpha-acyloxy thioether derivative follows the aim of green chemistry, solves the problems of high toxicity of sulfoxide and the like in the traditional preparation process of the alpha-acyloxy thioether derivative, and has the advantages of few types of catalyst raw materials, simple catalyst reaction process, simple and convenient product purification method, high yield and industrial value.)

1. A process for preparing an α -acyloxysulfide derivative, characterized in that: the structural formula is as follows:

wherein R is any one of alkyl, aryl or heteroaryl, R¹Is any one of alkyl, aryl or heteroaryl, R²Is any one of halogen or alkyl.

2. The method according to claim 1, wherein the compound a, the carboxylic acid B, the sodium salt of the carboxylic acid B, and the 1-chloromethyl-4-fluoro-1, 4-diazabicyclo [2.2.2] octane bis (tetrafluoroborate) salt are sequentially added into a sealed tube containing the reaction solvent acetonitrile, and the reaction solvent acetonitrile is distilled off to obtain the crude product of the α -acyloxysulfide derivative, wherein the structural formula of the compound a is as follows:

wherein R is¹Is any one of alkyl, aryl or heteroaryl, R²Is any one of halogen or alkyl.

3. The method according to claim 2, wherein the crude α -acyloxysulfide derivative is purified by column chromatography to obtain the α -acyloxysulfide derivative.

4. The method for producing an α -acyloxysulfide derivative according to claim 2, characterized in that the reaction temperature is 100 to 150 ℃.

5. The method for preparing a-acyloxysulfide derivative according to claim 2, characterized in that the reaction time is 12-36 hours.

6. The method for producing an α -acyloxysulfide derivative according to any one of claims 2 to 5, characterized in that the concentration of the reaction system is 0.1 mol/L.

7. The method according to claim 6, wherein the molar ratio of compound A, carboxylic acid B, sodium salt of carboxylic acid B and 1-chloromethyl-4-fluoro-1, 4-diazabicyclo [2.2.2] octane bis (tetrafluoroborate) salt is 1: 1: 3: 1.

8. the method according to claim 4, wherein the reaction temperature is 120 ℃.

9. The method according to claim 5, wherein the reaction time is 24 hours.

10. The method of claim 2, wherein the sealed pipe is a thick-walled pressure-resistant pipe.

Technical Field

The invention belongs to the field of fine chemical engineering, and particularly relates to a method for preparing an alpha-acyloxy thioether derivative.

Background

The alpha-acyloxysulfide is an important organic compound, the parent structure of the alpha-acyloxysulfide is widely existed in different natural products, and the derivative is an important organic synthesis intermediate and can be used for synthesizing aldehyde and ketone compounds. Therefore, how to directly and efficiently synthesize the compounds has attracted great attention from chemists.

At present, two types of methods are mainly used for synthesizing alpha-acyloxy thioether, wherein the first method uses a sulfoxide compound as a raw material and utilizes a Pummerer rearrangement reaction to synthesize the alpha-acyloxy thioether, and the method has the defect that the sulfoxide raw material needs to be synthesized in advance; secondly, thioether compounds are used as raw materials, under the action of a transition metal catalyst or a phase transfer catalyst, the thioether compounds are converted into alpha-acyloxy thioether by using a corresponding high-valence iodine reagent, and the defects of the reaction mainly lie in the high-valence iodine reagent which is high in price and high in activity.

In view of the above-mentioned drawbacks of the prior art, the present inventors have developed a method for preparing an α -acyloxysulfide derivative by means of extensive experience and expertise over many years, together with theoretical analysis, and have developed a method for green and efficient synthesis of an α -acyloxysulfide derivative by using a simple carboxylic acid, a corresponding carboxylate, and a commercial Selectfluor reagent, without preparing the corresponding sulfoxide in advance and using an expensive catalyst. Has industrial value.

Disclosure of Invention

The invention aims to provide a method for preparing alpha-acyloxy thioether derivatives, which follows the aim of green chemistry, solves the problems of low yield, high toxicity of sulfoxide raw materials and the like in the traditional process for preparing the alpha-acyloxy thioether derivatives, and simultaneously has simple reaction process and high product yield of the used catalyst, thereby greatly reducing the cost for preparing the alpha-acyloxy thioether derivatives and having industrial value.

The technical purpose of the invention is realized by the following technical scheme:

the invention provides an alpha-acyloxy thioether derivative, the structural formula of which is as follows:

wherein R is any one of alkyl, aryl or heteroaryl, R¹Is any one of alkyl, aryl or heteroaryl, R²Is any one of halogen or alkyl.

Further, the method for preparing the alpha-acyloxysulfide derivative provided by the invention comprises the following steps of sequentially adding the compound A, the carboxylic acid B, the sodium salt of the carboxylic acid B and the 1-chloromethyl-4-fluoro-1, 4-diazabicyclo [2.2.2] octane bis (tetrafluoroborate) salt into a sealed tube containing a reaction solvent acetonitrile, reacting, and distilling off the reaction solvent acetonitrile to obtain a crude product of the alpha-acyloxysulfide derivative, wherein the structural formula of the compound A is as follows:

the reaction formula is as follows:

wherein R is¹Is any one of alkyl, aryl or heteroaryl, R²Is any one of halogen or alkyl.

The invention provides a new preparation technical path of the alpha-acyloxy thioether derivative by the way, and the reaction mechanism is as follows: the method comprises the steps of obtaining a fluorine positive ion intermediate A by a substrate under the action of 1-chloromethyl-4-fluorine-1, 4-diazabicyclo [2.2.2] octane di (tetrafluoroborate), performing molecular internal ring closure under the action of sodium acetate to obtain a cyclic positive ion intermediate C, eliminating hydrogen at the alpha position of a sulfur atom of the intermediate C under the action of sodium acetate and acetic acid, performing N-S fracture to obtain a sulfur positive ion intermediate D and an isomerization product E thereof, and finally performing addition on the E and OAc negative ions to obtain a final product.

Further, purifying the crude product of the alpha-acyloxy thioether derivative by a column chromatography to obtain the alpha-acyloxy thioether derivative, wherein a developing solvent adopted by the column chromatography is dichloromethane.

Further, in the preparation method provided by the invention, the reaction temperature is 100-150 ℃. If the temperature is lower than 100 ℃, the reaction does not occur, and if the temperature is higher than 150 ℃, the risk of the reaction increases.

Further, in the preparation method provided by the invention, the reaction time is 12-36 hours.

Furthermore, in the preparation method provided by the invention, the concentration of the reaction system is 0.05-0.3 mol/L.

Furthermore, in the preparation method provided by the invention, the concentration of the reaction system is 0.1 mol/L.

Further, the molar ratio of the compound a, the carboxylic acid B, the sodium salt of the carboxylic acid B, and the 1-chloromethyl-4-fluoro-1, 4-diazabicyclo [2.2.2] octane bis (tetrafluoroborate) salt is 1: 1: 3: 1.

further, the reaction temperature in the present invention is preferably 120 ℃.

Further, the reaction time in the present invention is preferably 24 hours.

Furthermore, in the preparation method provided by the invention, the adopted seal pipe is preferably a thick-wall pressure-resistant pipe.

Further, the compound a is preferably N-substituted-2-methylthiobenzamide, which is added with carboxylic acid B, sodium salt of carboxylic acid B and 1-chloromethyl-4-fluoro-1, 4-diazabicyclo [2.2.2] octane bis (tetrafluoroborate) salt [ Selectfluor ] into a sealed tube containing a reaction solvent acetonitrile to perform reaction, and after the reaction is finished, the reaction solution is sequentially concentrated and separated by column chromatography to obtain the target product [ (2-substituted carbamoylaryl) thio ] carboxylic acid methyl ester.

In conclusion, the invention has the following beneficial effects:

the method for preparing the alpha-acyloxy thioether derivative follows the aim of green chemistry, solves the problems of low yield, high toxicity of sulfoxide raw materials and the like in the traditional process for preparing the alpha-acyloxy thioether derivative, and simultaneously has simple reaction process and high product yield of the used catalyst, thereby greatly reducing the cost for preparing the alpha-acyloxy thioether derivative.

Drawings

FIG. 1 is a reaction scheme showing the preparation of methyl [ (2-n-butylcarbamoylphenyl) thio ] propionate according to example 1 of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the detailed description of the method for preparing the α -acyloxysulfide derivative according to the present invention is provided below.

An α -acyloxysulfide derivative having the following structural formula:

wherein R is any one of alkyl, aryl or heteroaryl, R¹Is any one of alkyl, aryl or heteroaryl, R²Is any one of halogen or alkyl.

The preparation method comprises the following steps:

sequentially adding a compound A, a carboxylic acid B, a sodium salt of the carboxylic acid B and 1-chloromethyl-4-fluoro-1, 4-diazabicyclo [2.2.2] octane bis (tetrafluoroborate) into a sealed tube containing a reaction solvent acetonitrile, reacting at 100-150 ℃ for 12-36 hours, evaporating the reaction solvent acetonitrile, and performing column chromatography to obtain the alpha-acyloxy thioether derivative, wherein the structural formula of the compound A is as follows:

the reaction formula is as follows:

wherein R is¹Is any one of alkyl, aryl or heteroaryl, R²Is halogenAn alkyl group or an alkyl group.

Example 1: alpha-acyloxysulfide derivative [ (2-n-butyl carbamoylphenyl) thio ] methyl acetate and preparation method thereof

Methyl [ (2-substituted carbamoylphenyl) thio ] carboxylate having the formula:

the preparation method comprises the following steps:

acetonitrile (10mL), N-N-butyl-2-methylthiobenzamide (1.0mmol, 0.223g), acetic acid (1.0mmol, 0.060g), sodium acetate (3.0mmol, 0.246g) and Selectfluor (1.0mmol, 0.355g) were added in this order to a 50mL lock tube, the reaction temperature was controlled at 120 ℃ and the reaction was stirred vigorously for 24 hours. After the reaction is finished, reaction liquid is concentrated and column chromatography separation is carried out in sequence, and methyl [ (2-n-butyl carbamoylphenyl) thio ] acetate is obtained, wherein the yield is 0.244g, and the yield is 87%.

The reaction formula is as follows:

example 2: the methyl ester of α -acyloxysulfide derivative [ (2-substituted carbamoylphenyl) thio ] carboxylic acid is prepared as follows:

general procedure for the synthesis of methyl [ (2-substituted carbamoylphenyl) thio ] carboxylates: acetonitrile (10mL), N-substituted-2-methylthiobenzamide (1.0mmol, 0.223g), carboxylic acid B (1.0mmol), the sodium salt of carboxylic acid B (3.0mmol), and Selectfluor (1.0mmol, 0.355g) were added in this order to a 50mL lock tube, the reaction temperature was controlled at 120 ℃ and the reaction was stirred vigorously for 24 hours. After the reaction is finished, the reaction solution is concentrated and separated by column chromatography in turn, and then the [ (2-substituted carbamoylphenyl) thio ] carboxylic acid methyl ester is obtained.

Example 3: alpha-acyloxysulfide derivative [ (2-phenylcarbamoylphenyl) thio ] acetic acid methyl ester and preparation method thereof

Methyl [ (2-phenylcarbamoylphenyl) thio ] acetate was prepared in 40% yield from N-phenyl-2-methylthiobenzamide, sodium acetate and acetic acid by the method of example 1. The reaction formula is as follows:

example 4: alpha-acyloxysulfide derivative [ (2- (2-pyridyl) carbamoylphenyl) thio ] acetic acid methyl ester and preparation method thereof

Methyl [ (2- (2-pyridyl) carbamoylphenyl) thio ] acetate was prepared in 47% yield from N- (2-pyridyl) -2-methylthiobenzamide, sodium acetate and acetic acid by the method of example 1, according to the following reaction scheme:

example 5: alpha-acyloxysulfide derivative [ (2-n-butyl carbamoylphenyl) thio ] methyl propionate and preparation method thereof

Methyl [ (2-N-butylcarbamoylphenyl) thio ] propionate was prepared in 83% yield from N-butyl-2-methylthiobenzamide, sodium propionate and propionic acid by the method of example 1, according to the following reaction scheme:

example 6: alpha-acyloxysulfide derivative [ (2-n-butylcarbamoylphenyl) thio ] methyl benzoate and preparation method thereof

Methyl [ (2-N-butylcarbamoylphenyl) thio ] benzoate was prepared from N-butyl-2-methylthiobenzamide, sodium benzoate and benzoic acid in 71% yield by the preparation method of example 1, and the reaction formula is as follows:

example 7: alpha-acyloxysulfide derivative [ (2-n-butylcarbamoylphenyl) thio ] (5-chlorothiophene-2-benzoic acid) methyl ester and preparation method thereof

By using the preparation method of example 1, N-butyl-2-methylthiobenzamide, 5-chlorothiophene-2-sodium formate and 5-chlorothiophene-2-carboxylic acid were used as raw materials to prepare methyl [ (2-N-butylcarbamoylphenyl) thio ] (5-chlorothiophene-2-benzoic acid) ester with a yield of 78%, and the reaction formula was as follows:

example 8: alpha-acyloxysulfide derivative [ (2-n-butyl carbamoyl-5-methylphenyl) thio ] methyl propionate and preparation method thereof

Methyl [ (2-N-butylcarbamoyl-5-methylphenyl) thio ] propionate was prepared in 50% yield from N-butyl-4-methyl-2-methylthiobenzamide, sodium propionate and propionic acid by the method of example 1, according to the following reaction scheme:

example 9: alpha-acyloxysulfide derivative [ (2-n-butyl carbamoyl-4-chlorphenyl) thio ] methyl propionate and preparation method thereof

Methyl [ (2-N-butylcarbamoyl-4-chlorophenyl) thio ] propionate was prepared in 67% yield from N-butyl-5-chloro-2-methylthiobenzamide, sodium propionate and propionic acid by the method of example 1, according to the following reaction scheme:

comparative example 1

Acetonitrile (10mL), N-N-butyl-2-methylthiobenzamide (1.0mmol, 0.223g), acetic acid (1.0mmol, 0.060g) and sodium acetate (3.0mmol, 0.246g) were added sequentially in a 50mL sealed tube, the reaction temperature was controlled at 120 ℃ and the reaction was stirred vigorously for 24 hours. After the reaction is finished, reaction liquid is concentrated and separated by column chromatography in sequence, methyl [ (2-n-butyl carbamoylphenyl) thio ] acetate cannot be obtained by separation, and the formula involved in the reaction is as follows:

but no product was obtained.

Comparative example 2

The objective product could not be obtained from thioanisole by the method of example 1. The reaction formula is as follows:

comparative example 3

The preparation method of example 1 using N, N-diethylmethylthiobenzamide failed to obtain the desired product. The reaction formula is as follows:

the experimental results of the embodiments 1 to 9 show that the alpha-acyloxy thioether derivatives prepared by the preparation method of the invention can achieve the highest yield; as can be seen from comparative example 1, the reaction of the present invention could not occur in the absence of the catalyst Selectfluor reagent; as can be seen from comparative example 2, the reaction of the present invention takes place with the amide group in the ortho position; as is clear from comparative example 3, the reaction of the present invention requires hydrogen on the N of the amide group.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.