CN-122010679-A - Synthesis method of 2-methallyl chloride

Abstract

The invention relates to a method for synthesizing 2-methallyl chloride, which takes isobutene chlorine as a raw material and generates transposition rearrangement of free radical chlorine under the condition of ultraviolet irradiation to obtain the 2-methallyl chloride. The invention has the advantages of simple process and high conversion yield, and can change the byproduct, namely the isobutylene chlorine, in the process of preparing the 2-methallyl chloride by chlorination of the isobutylene into valuable substances, thereby improving the added value of the byproduct.

Inventors

• Cai Zhangji
• ZHOU BINBIN
• ZHU XIANCHAO

Assignees

• 宁波锦莱化工股份有限公司

Dates

Publication Date

20260512

Application Date

20241112

Claims (7)

1. 1. The method is characterized in that the method takes isobutene chlorine as a raw material, a photoinitiator is added, and chlorine translocation occurs under ultraviolet irradiation to prepare the 2-methallyl chloride.
2. 2. The method for synthesizing 2-methallyl chloride according to claim 1, wherein the method comprises the following steps: 。
3. 3. The method for synthesizing 2-methallyl chloride according to claim 1 or 2, wherein the ultraviolet light has a wavelength of 275nm to 380nm.
4. 4. The method for synthesizing 2-methallyl chloride according to claim 1 or 2, wherein the photoinitiator is a free radical photoinitiator, and the photoinitiator is used in an amount of 0.01-0.1% of the mass of the 2-methallyl chloride.
5. 5. The method for synthesizing 2-methallyl chloride according to claim 4, wherein the photoinitiator is any one of azoisobutyronitrile, azobisisoxyheptanenitrile, benzoyl peroxide, and tert-butyl peroxybenzoate.
6. 6. The method for synthesizing 2-methallyl chloride according to claim 4, wherein the photoinitiator is azoisobutyronitrile, and the amount of the photoinitiator is 0.02% of the mole number of 2-methallyl chloride.
7. 7. The method for synthesizing 2-methallyl chloride according to claim 1 or 2, wherein the reaction temperature of the method is from normal temperature to reflux state, and the reaction time is 2h-6h.

Description

Synthesis method of 2-methallyl chloride Technical Field The invention belongs to the field of fine chemical industry, relates to a synthesis process of organic matters, and particularly relates to a preparation method for converting isobutenyl chloride into 2-methallyl chloride by illumination. Background 2-Methallyl chloride, an important organic intermediate, has wide application in the chemical industry and can be used for synthesizing other compounds. The current process for the preparation of 2-methallyl chloride is essentially that of reacting isobutylene with chlorine to give 2-methallyl chloride. Because isobutene has relatively high reactivity, a large amount of byproducts such as isobutenyl chloride, tert-butyl chloride, 1, 2-dichloroisobutane, 3-dichloroisobutane and the like are generated in the chlorination reaction process. Besides the application value of the chloro-tert-butane, other byproducts can only be treated by waste solution, thus causing a great amount of waste. In order to increase the added value of the by-products, there is an urgent need to develop a method for converting the by-products into useful products from the raw materials. The invention develops a method for converting isobutene chlorine into 2-methallyl chloride by taking isobutene chlorine as a raw material. Disclosure of Invention Aiming at the problem that a large amount of byproducts are generated in the existing process of preparing 2-methallyl chloride by chloridizing isobutene, the invention further provides a method for converting isobutenyl chloride in the byproducts into main product 2-methallyl chloride again, and the added value of the byproducts is increased. The technical scheme of the invention is as follows: A synthesis method of 2-methallyl chloride takes isobutenyl chloride as a raw material, a photoinitiator is added, and chlorine translocation occurs under ultraviolet irradiation to prepare the 2-methallyl chloride. Further, the equation of the method is: 。 further, the wavelength of the ultraviolet light is 275nm-380nm. Further, the photoinitiator is a free radical photoinitiator, and the dosage of the photoinitiator is 0.01-0.1% of the mole number of 2-methylallyl chloride. Further, the photoinitiator is any one of azoisobutyronitrile, azobisisoheptonitrile, benzoyl peroxide or tert-butyl peroxybenzoate. Further, the photoinitiator is azoisobutyronitrile, and the dosage of the photoinitiator is 0.02 percent of the mass of the 2-methallyl chloride. Further, the reaction temperature of the method is in a state of normal temperature to reflux, and the reaction time is 2-6 h. The invention takes isobutene chlorine as a raw material, a photoinitiator is added, and chlorine translocation occurs under the irradiation of ultraviolet light with a certain wavelength to obtain 2-methallyl chloride. The structure of the raw material isobutenyl chloride in the invention is as follows:。 The structure of the product 2-methallyl chloride in the invention is as follows: 。 The reaction equation of the method of the invention is as follows: 。 The photoinitiator is a free radical photoinitiator and comprises azoisobutyronitrile, azobisisoxyheptonitrile, benzoyl peroxide, tert-butyl peroxybenzoate and the like, wherein azoisobutyronitrile is preferred; the photoinitiator is used in an amount of 0.01-0.1% by mass of 2-methallyl chloride, preferably 0.02% by mass; in the reaction, no dissolving reaction reagent is required to be added; the reaction temperature in the reaction is in a normal temperature to reflux state, and the preferable reaction temperature is controlled in the reflux state according to illumination time and intensity; the reaction time is about 2-6 h, and the conversion rate is about 20%. The invention has the advantages and beneficial effects that: (1) The invention develops a route for converting the byproduct waste isobutenyl chloride into the main product 2-methallyl chloride again. (2) The method has simple conversion conditions, and the single conversion rate can reach about 20 percent by utilizing ultraviolet light generated by a high-pressure mercury lamp to irradiate for about 2 to 6 hours (without other special device structures); (3) The method of the invention improves the byproduct value, reduces the emission of three wastes, and is environment-friendly and energy-saving. Detailed Description The invention is further illustrated by the following examples, which are not to be construed as limiting the scope of the invention as claimed. Example 1 Adding 12L of isobutylethenyl chloride into a 20L photoreaction kettle, adding 0.2g of azoisobutyronitrile, cooling a 250w mercury lamp by a built-in quartz jacket, refluxing a reaction system along with the prolongation of illumination time, performing gas phase detection reaction, reaching conversion balance for about 4 hours, stopping illumination, rectifying reaction liquid to separate out a product (compared with a 2-methallyl chloride standar