Method for preparing 1,3,4,6-hexamethyl-1,2,4-tetrahydronaphthalene by continuous reaction under catalysis of ionic liquid

A technology of hexamethylnaphthalene and ionic liquid, applied in the field of continuous reaction preparation of hexamethyltetralin under ionic liquid catalysis, can solve the problems of low total yield, long synthesis route, harsh reaction conditions, etc., and achieves improved automation, The effect of stable product quality and excellent regeneration performance

Inactive Publication Date: 2011-06-01
姜思田 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] There are deficiencies in the above-mentioned synthetic method in implementation. The synthetic method using toluene as raw material uses Grignard reagent, which has high cost and long synthetic route, which leads to lower total yield and has been gradually replaced by other methods; in many methods for preparing HMT Concentrated sulfuric acid is used as a catalyst in the medium, which is easy to corrode the equipment, and the waste acid is difficult to handle, and will lead to the production of macromolecular by-products, which is not conducive to industrial production; the current 3,3-dimethyl-1-butene or 2,3- Dimethyl-1-butene as the main raw material also has harsh reaction conditions in the synthetic method under the catalysis of acidic solid Lewis acid catalyst, poor reaction selectivity, relatively low reaction yield and yield, low reaction automation, and low reaction raw materials. Disadvantages such as high cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Under the protection of nitrogen, mix 175.5kg of chloro-n-butane and 147.6kg of N-methylimidazole into the autoclave, reflux for 48 hours at 85℃~105℃, cool and stand for stratification; pour to remove the upper layer Unreacted chloro-n-butane was extracted 3 times with 500L ethyl acetate; then 100L equal volume of acetonitrile-ethyl acetate mixture was added, shaken, frozen at -20°C for 12 hours, and the upper layer liquid was poured to obtain white The crystalline product (crude product), the crude product was vacuum dried at 90°C for 6 hours to obtain 298.9 kg of chloro-1-alkyl-3-methylimidazole ([C 4 H 9 min]Cl).

[0025] Under the protection of nitrogen, 179.8kg of anhydrous aluminum trichloride accurately measured is slowly added to 117.7kg of chloro-1-alkyl-3-methylimidazole ([C 4 H 9 min]Cl) and stirring, the reaction releases a lot of heat. To prevent the temperature of the reaction system from being too high, the preparation process needs to be carried out in a coo...

Embodiment 2

[0027] Under the protection of nitrogen, mix 185kg of bromo-n-butane and 147.6kg of N-methylimidazole into the reactor, replace with nitrogen three times and seal it, keep it at 85℃~105℃ for 30 hours, and obtain a colorless after cooling Alkyl bromide; precipitated with ethyl acetate, recrystallized with suction, washed with ethyl acetate, and dried in vacuo to obtain 287 kg of bromo-1-alkyl-3-methylimidazole ([C 4 H 9 min]Br).

[0028] Under the protection of nitrogen, 183kg of anhydrous iron trichloride accurately measured is slowly added to 120.5kg of bromo-1-alkyl-3-methylimidazole ([C 4 H 9 min]Br), and stirring, the reaction emits a lot of heat. In order to prevent the temperature of the reaction system from being too high, the preparation process needs to be carried out in a cooling kettle with a refrigerant. After the two substances are mixed and become transparent, the invention is obtained. Ionic liquid catalyst used.

[0029] 2. Preparation of hexamethyltetralin

Embodiment 3

[0031] Using the ionic liquid prepared in Example 1 as the catalyst, cyclohexane as the solvent, p-cymene and 3,3-dimethyl-1-butene as raw materials, the alkane was carried out in the presence of the hydrogen transfer reagent tert-butyl bromide. Alkylation reaction; the reaction temperature of the alkylation reaction is -30°C, and the reaction pressure is 1.0×10 3 Pa, the mass ratio of cumene to 3,3-dimethyl-1-butene is 1:1, the mass ratio of cumene to cyclohexane is 1:1, the hydrogen transfer reagent tert-butyl bromide The mass ratio to 3,3-dimethyl-1-butene is 0.5:1.

[0032] The specific process is: using a metering pump, pour p-cymene, cyclohexane, 3,3-dimethyl-1-butene, tert-butyl bromide and the preparation in Example 1 into the static mixer according to the proportions. The ionic liquid catalyst, in which the static mixer has a total length of 3000mm, an inner diameter of 60mm, and contains 50 units of Kenics spirals (left and right rotation alternately, twisted 180°), and...

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Abstract

The invention discloses a method for preparing 1,3,4,6-hexamethyl-1,2,4-tetrahydronaphthalene by continuous reaction under catalysis of ionic liquid, which comprises the steps of: with acid room-temperature ionic liquid as a catalyst, cyclic hydrocarbon as a solvent, and cymene and olefin as raw materials, conducting alkylation reaction in the existence of a hydrogen transfer reagent, wherein the acid room-temperature ionic liquid catalyst is prepared by reaction of metal halide and alkyl-containing pyridine halogenated amine, alkyl-containing hydrogen halide of amine or alkyl-containing halogenated amine of imidazole. The method for preparing 1,3,4,6-hexamethyl-1,2,4-tetrahydronaphthalene has simple technical process, higher product selectivity and relatively considerable yield; the ionic liquid catalyst adopted in reaction can be separated from the reacting liquid easily and can be recycled; and the three industrial wastes are not generated in the technical process, thus the method for preparing 1,3,4,6-hexamethyl-1,2,4-tetrahydronaphthalene is a green and environment-friendly technique.

Description

Technical field [0001] The invention belongs to the technical field of perfumes, and specifically relates to a method for preparing hexamethyltetralin by continuous reaction under the catalysis of an ionic liquid. Background technique [0002] Hexamethyltetralin is 1,1,3,4,4,6-hexamethyl-1,2,3,4-tetralin, abbreviated as HMT, which is an important intermediate in the synthesis of musk tuna fragrance, tuna Musk is a kind of musk fragrance. It has a strong musky fragrance, long-lasting fragrance, strong fragrance diffusion ability, plus its acid and alkali resistance, good light stability, no irritation to human skin, and good harmony with other spices. An ideal synthetic musk product with great development potential, has been widely used in perfume, cosmetics and detergent formulations. [0003] Since the study of nitro-free tetralin-based musk, people have successfully synthesized the intermediate hexamethyltetralin by different methods. (1) In the 1960s, the Polak Perfume Company...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C13/48C07C2/72
Inventor 姜思田姜深伟
Owner 姜思田
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