Method for continuously preparing 3-methyl-2-butenol

A technology of butenol and methyl, which is applied in the field of preparation of 3-methyl-2-butenol, an intermediate of spices, pharmaceuticals and pesticides, can solve the problems of high cost and low yield, and achieve the elimination of cost and raw materials Easy to obtain, less side effects

Inactive Publication Date: 2009-03-11
ZHEJIANG NHU CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This route reaction classic, esterification, alkali hydrolysis yield are high, and reaction is easy to control, but the yield of isoprene and hydrogen chloride reaction is lower, about 78% (pesticide 2004,43 (5): P228-229), cause The higher cost of synthesizing 3-methyl-2-butenol

Method used

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  • Method for continuously preparing 3-methyl-2-butenol
  • Method for continuously preparing 3-methyl-2-butenol
  • Method for continuously preparing 3-methyl-2-butenol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1-3

[0030] Example 1-3: Preparation of 3-methyl-2-butenol

[0031] A reaction device of 250m1 reactor with mechanical stirring, 1.5m rectification tower and thermometer is used. The rectification tower has 30 theoretical plates, and there is a side-line outlet at 10 plates from the bottom of the tower. The feed port of the reaction kettle uses a metering pump to accurately feed 2-methyl-3-buten-2-ol. Put in 100g 2-methyl-3-buten-2-ol, vanadium oxytetraisopentenol ester OV (OC 5 H 9 ) 4 10.0g, the 2-methyl-3-buten-2-ol feed was started after the temperature was raised to 140°C, and the crude 3-methyl-2-butenol was discharged from the side discharge port, keeping the reaction temperature at 140- 150°C. The feeding is finished, and the crude 3-methyl-2-butenol is directly distilled out under reduced pressure after the reaction is completed, and combined with the output of the side thread. Table 1 shows the reaction results of Examples 1-3:

[0032] Table 1

[0033] Response para...

Embodiment 4-6

[0034] Example 4-6: Preparation of 3-methyl-2-butenol

[0035]A reaction device with a 250ml reactor with mechanical stirring, 2.0m rectification tower and thermometer is used. The rectification tower has 40 theoretical plates, and there is a side-line outlet at 10 plates from the bottom of the tower. The feed port of the reaction kettle uses a metering pump to accurately feed 2-methyl-3-buten-2-ol. Put in 100g 2-methyl-3-buten-2-ol, vanadium oxytetraisopentenol ester OV(OC 5 H 9 ) 4 10.0g, the 2-methyl-3-buten-2-ol feed was started after the temperature was raised to 140°C, and the crude 3-methyl-2-butenol was discharged from the side discharge port, keeping the reaction temperature at 140- 150°C. After half of the 2-methyl-3-butene-2-ol is fed, 10.0g of vanadium oxotetraisopentenol ester is added to complete the feeding. After the reaction is completed, 3-methyl is directly distilled out under reduced pressure. The crude -2-butenol is combined with the discharge of the side line...

Embodiment 6

[0038] After rectifying and separating the crude 3-methyl-2-butenol obtained in Example 6, 1254.1 g of 3-methyl-2-butenol was obtained, with a content of 98.2%; 2-methyl-3-butene was recovered. The 2-alcohol 951.6g, the content is 98.5%.

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Abstract

The invention discloses a method for preparing intermediate 3-methyl-2-butenol. The prior method has the defects of rigorous conversion reaction condition, low conversion rate, difficult separation, and high technical requirement. The method has the following steps of: putting 2-methyl-3-butene-2-hydrin and rearrangement catalyst into a reaction kettle, and heating the 2-methyl-3-butene-2-hydrin and rearrangement catalyst to undergo a catalytical rearrangement reaction to obtain the mixture of the 2-methyl-3-butene-2-hydrin and the 3-methyl-2-butenol; separating the mixture through a rectification tower, recovering the 2-methyl-3-butene-2-hydrin at the top of the rectification tower and returning the 2-methyl-3-butene-2-hydrin to the reaction kettle for feeding, obtaining the crude product of the 3-methyl-2-butenol through discharging from a lateral line of the rectification tower, and continuously replenishing new 2-methyl-3-butene-2-hydrin into the reaction kettle. The method has the advantages of no use of solvent, mild reaction condition and easy control, and realizes the continuous production based on the continuous feeding and discharging.

Description

Technical field [0001] The invention relates to a preparation method of 3-methyl-2-butenol, an intermediate of spices, medicines and pesticides. Background technique [0002] 3-methyl-2-butenol, also known as prenol, can be used as a fragrance; 3-methyl-2-butenol derivative 3-methyl-2-butenol acetate It is also a spice and can also be used as a food additive. [0003] 3-Methyl-2-butenol is mainly used for the production of citral, isophytoalcohol (the main intermediate of VE), methyl bentinate, DV methyl chrysanthemum (intermediate of pyrethroid), synthesis of vitamin A, Carotene intermediates and rubber monomers are also used in other organic synthesis. [0004] The structural formula of 3-methyl-2-butenol is as follows: [0005] [0006] At present, 3-methyl-2-butenol mainly has the following synthetic methods: [0007] (1) Using 2-methyl-3-buten-2-ol as a raw material, it is directly converted into 3-methyl-2-butenol under catalyst conditions. US3925485: The reaction is carr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C33/03C07C29/56
Inventor 商志才钱洪胜王金明鲁国彬邱贵生
Owner ZHEJIANG NHU CO LTD
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