A kind of preparation method of citral

A technology of citral and dehydrolinalool, which is applied in the field of fine chemicals, can solve the problems of reduced catalyst activity, high catalyst cost, and reduced selectivity, and achieve the effects of fast conversion speed, reduced production cost, and simple operation

Active Publication Date: 2016-04-20
SHANDONG NHU PHARMA +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But the input amount of catalyst of this scheme is 4-6% of dehydrolinalool weight, and consumption is bigger, and along with the number of times of applying mechanically increases, by-product accumulates, and catalyst activity declines, and selectivity reduces
Therefore, this solution does not solve the problem of high catalyst cost

Method used

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  • A kind of preparation method of citral
  • A kind of preparation method of citral
  • A kind of preparation method of citral

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preparation example Construction

[0029] The preparation method of described citral, the catalyst used is molybdenum trioxide, heterogeneous catalysis. After the reaction is finished, the catalyst can be recycled by filtration, the reaction solution can be concentrated to obtain the citral product, and the final product can be obtained through rectification and purification.

[0030] The invention has high catalytic efficiency, good selectivity and fast transformation speed, and the reaction time is only 2.5-3 hours for complete transformation. The yield of citral can reach more than 95.8%.

Embodiment 1

[0032] A preparation method of citral, comprising the following steps:

[0033] a. Feeding

[0034] Put 100.0g of dehydrolinalool, 30.0g of dimethyl sulfoxide, 30.0g of acetic acid, and 300.0g of toluene into a 1000ml three-necked flask equipped with a stirrer, a thermometer, and a condenser, and simultaneously add 0.5g of molybdenum trioxide as a catalyst.

[0035] b. Response

[0036] Fully stir the input raw materials, raise the temperature to reflux, keep warm for reaction, control the reaction temperature at 80-140°C for reaction, and track and detect the reaction process by gas chromatography.

[0037] c, filtration, vacuum distillation

[0038] After the reaction was completed, the solid was filtered off, concentrated under reduced pressure and distilled under reduced pressure to obtain the finished product.

[0039] Gas chromatographic determination of content, the reaction results are as follows:

[0040]

[0041] According to the step of embodiment 1, change t...

Embodiment 2

[0056]The recovery of catalyst is applied mechanically: the catalyst recovered after filtering the reaction solution of Example 1 is put into a 1000ml three-necked flask equipped with a stirrer, a thermometer, and a condenser tube, and 100.0g dehydrolinalool, 30.0g dimethyl sulfoxide, 30.0 1 g of acetic acid and 300.0 g of toluene were fully stirred, the temperature was raised to reflux, and the temperature was maintained for reaction, and the reaction process was tracked and detected by gas chromatography. After the reaction was completed, the solid was filtered off, concentrated under reduced pressure and distilled under reduced pressure. Measure content by gas chromatography, reaction result is as follows:

[0057]

[0058] It can be seen from the above table that the reaction effect is better after the catalyst is recovered and applied mechanically, and the citral content reaches 98.5%.

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Abstract

The invention discloses a preparation method of citral, which uses dehydrolinalool as a raw material and molybdenum trioxide as a catalyst. In the presence of acid, citral is obtained by catalytic rearrangement in an organic inert solvent; the catalyst used in the preparation method is cheap; the amount of catalyst used is small; the catalytic efficiency is high; the reaction selectivity is good and the yield is high; Short; the catalyst can be recycled and applied.

Description

technical field [0001] The invention relates to a preparation method for producing citral by catalytic rearrangement of dehydrolinalool as a raw material, which belongs to the field of fine chemical industry. Background technique [0002] Citral has a strong lemon fragrance and has two cis-trans isomers, geranial and neral. Citral has a wide range of uses. It can be used for fragrance of daily chemical products such as perfumes, as well as edible spices. It is also an important chemical intermediate used in the synthesis of ionones (raw materials for the synthesis of vitamins A, E and carotene), Citrilonitrile, Methylionone, Hydroxycitronellal, Isopulegol, Damascone and other compounds. [0003] Citral occurs naturally in litsea cubeba oil and can be extracted by distillation under reduced pressure. However, limited by the source of raw materials and the efficiency of the production process, it does not meet the requirements of modern chemical mass production. Can not mee...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C47/21C07C45/51
CPCY02P20/584
Inventor 李聪聪王海泉宋江胡晓恵马啸胡水涛
Owner SHANDONG NHU PHARMA
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