阅读说明：本技术 一种制备δ-戊内酯的新方法 (New method for preparing valerolactone ) 是由 刘俊霞 陈景润 张伟 于 2020-05-28 设计创作，主要内容包括：一种制备δ-戊内酯的新方法,属于根据原料分子和产物分子的结构相似性利用分子筛催化羰基化制备环状内酯的技术领域,其特征在于：以四氢呋喃和一氧化碳为原料,充分利用四氢呋喃分子的已有结构,采用分子筛为催化剂,一步催化羰基化制备得到δ-戊内酯。根据四氢呋喃和δ-戊内酯分子结构的相似性,通过催化一氧化碳增碳的策略一步转化得到δ-戊内酯,以H-MOR为催化剂,通过H-MOR催化剂催化羰基化反应一步得到高端化学品δ-戊内酯。该方法原料四氢呋喃廉价易得、分子筛催化剂易于制备,而且反应条件温和、反应过程简单,具有良好的工业应用前景。(A new method for preparing valerolactone belongs to the technical field of preparing cyclic lactone by catalyzing and carbonylating with molecular sieves according to the structural similarity of raw material molecules and product molecules, and is characterized in that: tetrahydrofuran and carbon monoxide are used as raw materials, the existing structure of tetrahydrofuran molecules is fully utilized, a molecular sieve is used as a catalyst, and the valerolactone is prepared by one-step catalytic carbonylation. According to the similarity of molecular structures of tetrahydrofuran and valerolactone, the valerolactone is obtained by one-step conversion through a strategy of catalyzing carbon monoxide to increase carbon, and the high-end chemical valerolactone is obtained by one-step catalytic carbonylation reaction through an H-MOR catalyst by taking the H-MOR as a catalyst. The method has the advantages of cheap and easily-obtained raw material tetrahydrofuran, easy preparation of the molecular sieve catalyst, mild reaction conditions, simple reaction process and good industrial application prospect.)

1. A novel method for preparing valerolactone, which is characterized by comprising the following steps: tetrahydrofuran and carbon monoxide are used as raw materials, the existing structure of tetrahydrofuran molecules is fully utilized, a molecular sieve is used as a catalyst, and the valerolactone is prepared by one-step catalytic carbonylation.

2. The novel process for the preparation of valerolactone according to claim 1, wherein: the catalyst is H-MOR molecular sieve.

3. A novel process for the preparation of valerolactone according to claim 1 or 2, wherein: the catalyst is an H-MOR molecular sieve with the silicon-aluminum ratio of 5-10.

4. A novel process for the preparation of valerolactone according to claim 3, wherein: the catalyst H-MOR molecular sieve needs to be roasted at 480-550 ℃ for 6-10H.

5. The novel process for the preparation of valerolactone according to claim 4, wherein: the catalyst H-MOR molecular sieve is used for catalyzing tetrahydrofuran and carbon monoxide on a fixed bed reaction device to carry out carbonylation to prepare valerolactone.

6. The novel process for the preparation of valerolactone according to claim 5, wherein: the inner diameter of a reaction tube of the fixed bed reaction device is 10mm, the length of the reaction tube is 40cm, the loading of the catalyst is 0.5g, and the catalyst is N before reaction₂Pretreating for 1h at 300 ℃ in the atmosphere, adjusting the reaction temperature and reaction pressure required by the reaction, introducing reaction raw material gas for reaction, and introducing the gas after the reaction into an online chromatograph for analysis through a heated pipeline.

7. The novel process for the preparation of valerolactone according to claim 6, wherein: the raw material gas is introduced into a saturated tube by adopting nitrogen to carry tetrahydrofuran for feeding.

8. The novel process for the preparation of valerolactone according to claim 6, wherein: the reaction temperature is 100-180 ℃.

9. The novel process for the preparation of valerolactone according to claim 8, wherein: the reaction pressure is 1-5 MPa.

Technical Field

The invention belongs to the technical field of preparing cyclic lactone by catalyzing carbonylation with a molecular sieve according to the structural similarity of a raw material molecule and a product molecule, and particularly relates to a novel method for preparing valerolactone.

Background

Valerolactone is an important starting material for organic intermediates and intermediates in the pharmaceutical industry. Has wide application in the aspects of synthetic fiber (polyester), medicine, plant protective agent and the like. Because the ring-opening polymerization reaction is easy to occur and the reaction can be carried out spontaneously, the produced high molecular polyester has the characteristic of biodegradability and can be applied to the fields of materials, medicines and the like. At present, valerolactone required by China mainly depends on import, only a few companies produce internationally, and only two companies produce domestically. In recent years, the market demand has increased due to the expansion of the use of valerolactone, and the price of valerolactone has been increasing.

With the continuous expansion of valerolactone application, especially the application prospect in the aspects of medicine and environmental protection, the future demand will be expected to increase continuously, so the existing process technology must be renovated to find a synthetic process route with mild reaction conditions and good economic benefits.

At present, many raw materials for preparing valerolactone in a laboratory mainly comprise cyclopentanone, 1, 5-pentanediol, 1, 5-glutaraldehyde, -chloropentanoic acid, 2-methyl crotonate, 1-hydroxypentanoic acid and the like. Can realize a cyclopentanone oxidation method and a 1, 5-pentanediol oxidation method which are industrially applied. The peroxyacid is used as an oxidizing agent to oxidize cyclopentanone to synthesize valerolactone, the reaction is a typical Baeyer-Villiger oxidation reaction, and in the process of synthesizing valerolactone by oxidizing cyclopentanone with peroxyacid, peroxyorganic acid is used for oxygenizing and synthesizing the cyclopentanone, the yield is high, but the peroxyacid has high toxicity and high price. The peroxyacid method is not widely used in industry because, on one hand, the reaction involves organic acid, but the corresponding organic acid brings great trouble to the later separation and treatment, thereby increasing the cost of industrial application; on the other hand, most peroxy acids are unstable, so that the peroxy acids used in laboratories are prepared at present and are generally obtained by oxidizing corresponding organic acids with high-concentration hydrogen peroxide, but the generated organic acids are difficult to recycle, and the industrial production of the organic acids is limited; also, since peroxy acids are not very stable in nature and are easily exploded at high temperatures or in the presence of severe impact, they are very inconvenient to transport and store. Many researchers continue to explore the process. However, the cyclopentanone oxidation method requires comprehensive consideration of various factors such as raw materials and reaction conditions. Later hydrogen peroxide oxidation was developed, which theoretically should produce both H2O and valerolactone, according to the reaction mechanism, but by-products of the reaction are glutaric acid and dicyclopentanone peroxide. If the yield of valerolactone is to be increased, the occurrence of side reactions and competing reactions must be suppressed, which is also a problem to be solved for industrial mass production using hydrogen peroxide as an oxidizing agent. Oxygen is an oxidant which is cheap, clean, pollution-free and safer, and the synthesis of valerolactone by using oxygen as the oxidant meets the development direction of green chemistry, but aldehyde is generally used as a co-oxidant due to poor oxidizing capability, but the price is relatively high.

Disclosure of Invention

The invention aims to solve the problems and provides a novel route for preparing valerolactone from cheap and easily available raw materials.

The novel method for preparing valerolactone takes tetrahydrofuran and carbon monoxide as raw materials, fully utilizes the existing structure of tetrahydrofuran molecules, adopts a molecular sieve as a catalyst, and prepares the valerolactone by one-step catalytic carbonylation.

Preferably, in the novel method for preparing valerolactone, the catalyst is H-MOR molecular sieve.

Preferably, in the novel method for preparing valerolactone, the catalyst is an H-MOR molecular sieve with the silicon-aluminum ratio of 5-10.

Further, in the novel method for preparing valerolactone, the catalyst H-MOR molecular sieve needs to be roasted for 6-10H at 480-550 ℃.

Preferably, the novel method for preparing valerolactone, provided by the invention, is used for evaluating the reaction of catalyzing tetrahydrofuran and carbon monoxide to prepare valerolactone by the catalyst H-MOR molecular sieve in a fixed bed reaction device.

Preferably, in the novel method for preparing valerolactone, the reaction tube of the fixed bed reaction device has the inner diameter of 10mm and the length of 40cm, the loading of the catalyst is 0.5g, and the catalyst is added in N before the reaction₂Pretreating for 1h at 300 ℃ in the atmosphere, adjusting the reaction temperature and reaction pressure required by the reaction, introducing reaction raw material gas for reaction, and introducing the gas after the reaction into an online chromatograph for analysis through a heated pipeline.

Preferably, in the novel method for preparing valerolactone, the feed gas is fed with tetrahydrofuran by introducing nitrogen into a saturation tube.

Preferably, in the novel process for the preparation of valerolactone according to the invention, the reaction temperature is 100-180 ℃.

Preferably, in the novel method for preparing valerolactone, the reaction pressure is 1-5 MPa.

According to the novel method for preparing valerolactone, disclosed by the invention, according to the similarity of molecular structures of tetrahydrofuran and valerolactone, valerolactone is obtained by one-step conversion through a strategy of catalyzing carbon monoxide to increase carbon, and a high-end chemical, namely valerolactone, is obtained by one-step catalytic carbonylation reaction through an H-MOR catalyst by taking H-MOR as a catalyst. The method has the advantages of cheap and easily-obtained raw material tetrahydrofuran, easy preparation of the molecular sieve catalyst, mild reaction conditions, simple reaction process and good industrial application prospect.

Detailed Description

The novel process for the preparation of valerolactone according to the invention is illustrated in detail by the examples below.