阅读说明：本技术 一种环丁酮的制备方法 (Preparation method of cyclobutanone ) 是由 李红功 韦幸红 史梦婷 于 2020-07-30 设计创作，主要内容包括：本发明涉及有机合成技术领域,具体涉及一种环丁酮的制备方法,包括如下步骤：三氯乙酰氯在锌粉、三氯氧磷作用下,生成二氯乙烯酮；二氯乙烯酮与乙炔发生环加成反应,生成二氯环丁烯酮；在催化剂作用下,二氯环丁烯酮进行氢化反应得到环丁酮。本发明提供的环丁酮的制备方法反应原料价廉易得,反应步骤简单,收率较高,具有良好的工业化前景。(The invention relates to the technical field of organic synthesis, in particular to a preparation method of cyclobutanone, which comprises the following steps: under the action of zinc powder and phosphorus oxychloride, trichloroacetyl chloride generates dichloroketene; performing cycloaddition reaction on dichloroketene and acetylene to generate dichlorocyclobutenone; under the action of catalyst, dichloro cyclobutenone is hydrogenated to obtain cyclobutanone. The preparation method of the cyclobutanone provided by the invention has the advantages of cheap and easily available reaction raw materials, simple reaction steps, higher yield and good industrial prospect.)

1. The synthetic method of cyclobutanone is characterized by comprising the following steps:

(1) under the action of zinc powder and phosphorus oxychloride, trichloroacetyl chloride generates dichloroketene; performing cycloaddition reaction on dichloroketene and acetylene to generate dichlorocyclobutenone;

(2) under the action of a catalyst, performing hydrogenation reaction on dichlorocyclobutenone to obtain cyclobutanone; the specific reaction formula is as follows:

2. the method for synthesizing cyclobutanone according to claim 1, wherein the molar ratio of trichloroacetyl chloride, zinc powder, phosphorus oxychloride and acetylene in step (1) is 1: 1-3: 1-3: 1 to 10.

3. The method for synthesizing cyclobutanone according to claim 1, wherein the reaction temperature in step (1) is 30-80 ℃.

4. The method for synthesizing cyclobutanone according to claim 1, wherein the hydrogenation reaction in step (2) comprises selective double bond hydrogenation and dechlorination hydrogenolysis.

5. The method for synthesizing cyclobutanone according to claim 1, wherein the catalyst used in the hydrogenation reaction in step (2) is Pt/Al₂O₃、Pd/Al₂O₃Supported catalysts or nickel-based catalysts.

6. The method for synthesizing cyclobutanone according to claim 5, wherein the amount of the catalyst used in step (2) is 1-20% by weight of the substrate.

7. The method for synthesizing cyclobutanone according to claim 1, wherein an organic base is further added as an acid-addition agent in step (2).

8. The method for synthesizing cyclobutanone according to claim 7, wherein the organic base used in step (2) is selected from tertiary amines such as triethylamine, tri-N-butylamine, diisopropylethylamine, and N, N-dimethylaniline.

9. The method for synthesizing cyclobutanone according to claim 1, wherein the hydrogen pressure in step (2) is from atmospheric pressure to 0.5 Mpa.

10. The method for synthesizing cyclobutanone according to claim 7, wherein the molar ratio of trichloroacetyl chloride added in step (1) to organic base added in step (2) in the reaction is 1: 1 to 5.

Technical Field

The invention relates to the technical field of organic synthesis, in particular to a preparation method of cyclobutanone.

Background

The compound cyclobutanone, CAS number 1191-95-3, England name: cyclobutanone is an important medical intermediate. The structural formula of the product is as follows:

with respect to the synthesis of cyclobutanone, US6476274A discloses the synthetic route: cyclopropyl methyl alcohol is used as a raw material, the raw material is rearranged in a hydrochloric acid aqueous solution to obtain a cyclobutylmethyl alcohol crude product, and then the cyclobutylmethyl alcohol crude product is directly oxidized by sodium hypochlorite to obtain cyclobutanone. The product obtained by the reaction route contains a plurality of impurities with close boiling points, such as cyclopropylformaldehyde, 3-butenal, cyclobutylchloride and cyclopropylmethanol, so that the purification of the finished product is difficult, and the high-purity product is difficult to obtain with high yield, and the purity of the literature is only 95.5% (GC). And the route uses expensive cyclopropyl methanol as a starting material, so that the product cost is higher.

Synthesis; nb.9; (1983) (ii) a The method disclosed in p.721 is: preparing a Grignard reagent from 1, 3-dibromopropane and magnesium metal, introducing carbon dioxide, hydrolyzing with dilute hydrochloric acid, extracting for layering, and rectifying to obtain cyclobutanone product with the yield of 13 percent (calculated by 1, 3-dibromopropane). Although the price of the starting raw material is not high, the total yield is too low, so that the three wastes and byproducts are too much, the operation is complex, and the industrial value is lacked.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: provides a method for synthesizing cyclobutanone with good economical efficiency and high product purity.

The technical scheme for solving the technical problems is as follows:

the synthetic method of cyclobutanone is characterized by comprising the following steps:

(1) under the action of zinc powder and phosphorus oxychloride, trichloroacetyl chloride generates dichloroketene; dichloroketene and acetylene are subjected to [ 2+2 ] cycloaddition reaction to generate dichlorocyclobutenone;

(2) under the action of a catalyst, performing hydrogenation reaction on dichlorocyclobutenone to obtain cyclobutanone; the specific reaction formula is as follows:

preferably, in the step (1), the molar ratio of trichloroacetyl chloride, zinc powder, phosphorus oxychloride to acetylene is 1: 1-3: 1-3: 1-10; further, in the step (1), the molar ratio of trichloroacetyl chloride, zinc powder, phosphorus oxychloride to acetylene is 1: 1-2: 1-2: 1.05-5; furthermore, in the step (1), the molar ratio of trichloroacetyl chloride, zinc powder, phosphorus oxychloride and acetylene is 1: 1-1.5: 1-1.5: 1.1 to 2.

Preferably, the reaction temperature in the step (1) is 30-80 ℃; further, the reaction temperature in the step (1) is 40-60 ℃.

Preferably, the hydrogenation reaction in the step (2) includes selective double bond hydrogenation and dechlorination hydrogenolysis.

Preferably, the catalyst used in the hydrogenation reaction in the step (2) is Pt/Al₂O₃、Pd/Al₂O₃Supported catalysts or nickel-based catalysts.

Preferably, the amount of the catalyst used in the step (2) is 1-20% of the weight of the substrate; further, the amount of the catalyst used in the step (2) is 3-10% of the weight of the substrate. The substrate is the product of step (1).

Preferably, an organic base is further added in the step (2) as an acid-removing agent for absorbing hydrogen chloride generated in the dechlorination hydrogenolysis reaction.

Preferably, the organic base used in step (2) is selected from tertiary amines such as triethylamine, tri-N-butylamine, diisopropylethylamine, and N, N-dimethylaniline.

Preferably, the hydrogen pressure in the step (2) is from normal pressure to 0.5 Mpa; further, the hydrogen pressure in the step (2) is 0.05-0.2 Mpa.

Preferably, the reaction temperature in the step (2) is 0-50 ℃; preferably, the reaction temperature in the step (2) is 20-30 ℃.

Preferably, the molar ratio of the trichloroacetyl chloride added in the step (1) to the organic base added in the step (2) in the reaction is 1: 1-5; further in the reaction, the molar ratio of the trichloroacetyl chloride added in the step (1) to the organic base added in the step (2) is 1: 1.1 to 2.

The Chinese naming of the compound of the invention conflicts with the structural formula, and the structural formula is taken as the standard; except for obvious errors in the formula.

The preparation method of the cyclobutanone provided by the invention has the advantages of cheap and easily available reaction raw materials, simple reaction steps, higher yield and good industrial prospect.

Detailed Description

The invention is illustrated but not limited by the following examples. The technical solutions protected by the present invention are all the simple replacements or modifications made by the skilled person in the art.