阅读说明：本技术 一种檀香醚的制备方法 (Preparation method of sandalwood ether ) 是由 江承艳 柯诗祺 于 2020-04-22 设计创作，主要内容包括：本发明涉及一种檀香醚的制备方法。具体地,本发明提供一种檀香醚的制备方法,所述的方法包括步骤,在有机溶剂中,在水合催化剂的作用下,甲氧基二氢月桂烯和水发生水合反应生成檀香醚。本发明所述的方法具有高收率、高转化率等优异技术效果,且工艺简单,适合工业化生产。(The invention relates to a preparation method of sandalwood ether. Specifically, the invention provides a preparation method of sandalwood ether, which comprises the step of carrying out hydration reaction on methoxy dihydromyrcene and water in an organic solvent under the action of a hydration catalyst to generate sandalwood ether. The method has the excellent technical effects of high yield, high conversion rate and the like, is simple in process, and is suitable for industrial production.)

1. A method for preparing a santalene ether, characterized in that the method comprises the steps of:

(i) in an organic solvent, under the action of a hydration catalyst, carrying out hydration reaction on methoxy dihydromyrcene and water to generate sandalwood ether;

wherein the hydration catalyst comprises a first catalyst and a second catalyst;

the first catalyst is a solid acid catalyst, the solid acid catalyst comprises a solid acid and a first metal active component, the first metal active component is loaded on the solid acid, and the first metal active component is selected from the following group: platinum, nickel, molybdenum, or a combination thereof;

the second catalyst comprises a modified cation exchange resin loaded with a second metal active component;

the modified cation exchange resin is subjected to strong acid soaking treatment;

the second metal active component is selected from the group consisting of: zinc chloride, aluminum chloride, tin chloride, ruthenium chloride, rhodium chloride, or combinations thereof.

2. The method of claim 1, wherein the methoxydihydromyrcene is prepared by:

(ii) under the action of an alcohol synthesis catalyst, reacting dihydromyrcene with methanol to generate methoxy dihydromyrcene;

the catalyst is modified cation exchange resin, and the modified cation exchange resin is cation exchange resin soaked by strong acid.

3. The method of claim 1, wherein in step (i), the organic solvent is selected from the group consisting of: isopropanol, tetrahydrofuran, acetone, methyltetrahydrofuran, dioxane, acetic acid, acetate, or combinations thereof.

4. The method of claim 1, wherein the solid acid catalyst is prepared by a process comprising the steps of:

impregnating a solid acid with a solution of a material selected from the group consisting of: soaking platinic chloride, nickel nitrate hexahydrate, ammonium molybdate tetrahydrate or their mixture, drying and roasting to obtain solid acid catalyst;

the solid acid is selected from the following group: zeolite, silica, alumina, or combinations thereof.

5. The process of claim 1, wherein the weight percent of platinum based on the solid acid catalyst is from 0.1 to 2.5 wt.%, preferably from 0.1 to 2 wt.%, more preferably from 0.1 to 1.5 wt.%, more preferably from 0.2 to 0.8 wt.%, and most preferably from 0.3 to 0.7 wt.%;

the weight percentage of the nickel in the solid acid catalyst is 0.05-1.5 wt%, preferably 0.08-1.0 wt%, more preferably 0.08-0.5 wt%, and most preferably 0.1-0.3 wt%; and/or

The weight percentage of the molybdenum in the solid acid catalyst is 0.05-2 wt%, preferably 0.5-2 wt%, more preferably 0.8-1.5 wt%, most preferably 1-1.5 wt%.

6. The process of claim 1 wherein said second metal active component comprises from 0.5 to 20 wt%, preferably from 1 to 15 wt%, more preferably from 2 to 12 wt%, most preferably from 4 to 10 wt%, more preferably from 4 to 8 wt% of said modified cation exchange resin in said second catalyst.

7. The method of claim 1, wherein the method comprises one or more features selected from the group consisting of:

in the second catalyst, the zinc chloride accounts for 0.5-20 wt%, preferably 1-15 wt%, more preferably 2-12 wt%, most preferably 4-10 wt%, more preferably 4-8 wt% of the modified cation exchange resin;

in the second catalyst, the aluminum chloride accounts for 0.5-20 wt%, preferably 1-15 wt%, more preferably 2-12 wt%, most preferably 4-10 wt%, more preferably 4-8 wt% of the modified cation exchange resin;

in the second catalyst, the weight percentage of the tin chloride in the modified cation exchange resin is 0.5-20 wt%, preferably 1-15 wt%, more preferably 2-12 wt%, most preferably 4-10 wt%, more preferably 4-8 wt%; and/or

In the second catalyst, the ruthenium chloride accounts for 0.5-20 wt%, preferably 1-15 wt%, more preferably 2-12 wt%, most preferably 4-10 wt%, and most preferably 4-8 wt% of the modified cation exchange resin.

8. The process of claim 1, wherein the weight ratio of the first catalyst to the second catalyst is from 0.5 to 5: 1, preferably 0.5-4:1, more preferably 1-2:1, more preferably 1.2-2:1, more preferably 1.3-1.8: 1.

9. The method of claim 1, wherein the second catalyst is prepared by:

(a) providing a cation exchange resin and a second metal active component;

(b) soaking cation exchange resin in strong acid to obtain modified cation exchange resin;

(c) and mixing the modified cation exchange resin and the second metal active component in an anhydrous solvent, reacting, and filtering to obtain the second catalyst.

10. A hydration catalyst, wherein the hydration catalyst comprises a first catalyst and a second catalyst;

the first catalyst is a solid acid catalyst, the solid acid catalyst comprises a solid acid and a first metal active component, the first metal active component is loaded on the solid acid, and the first metal active component is selected from the following group: platinum, nickel, molybdenum, or a combination thereof;

the second catalyst comprises a modified cation exchange resin loaded with a second metal active component;

the modified cation exchange resin is subjected to strong acid soaking treatment;

the second metal active component is selected from the group consisting of: zinc chloride, aluminum chloride, tin chloride, ruthenium chloride, rhodium chloride, or combinations thereof.

Technical Field

The invention relates to the technical field of spice synthesis, and particularly relates to a preparation method of sandalwood ether.

Background

The chemical formula of the sandalwood ether is C₁₁H₂₄O₂And the English name is Osyrol. It is a colorless transparent liquid, stable in chemical property, small in volatility, good in colour and not easy to change colour, so that it is an ideal colour tone for preparing essence and perfume. The sandalwood ether has strong fragrance of sandalwood and flower, and is also good for fixingThe perfume can improve the durability and stability of the essence. Therefore, research and development of synthetic sandalwood have practical significance.

Sandalwood ether was first developed and successfully marketed by perfumery in the uk. The route adopts pinene as a raw material, and the pinene is firstly converted into pinane through hydrogenation reaction; then, carrying out high-temperature pyrolysis and ring opening to obtain dihydromyrcene; then taking methanol as a solvent and a reaction substrate to react with dihydromyrcene to generate a methoxy dihydromyrcene compound; then epoxidation is carried out by using oxide and hydrogenation reaction is carried out under the catalysis of Raney nickel to obtain the product. Because the process is developed for a relatively long time, the existing problems are more obvious: the methoxylation reaction needs to be carried out under the catalysis of inorganic acid (sulfuric acid, phosphoric acid and the like), and has the defects of high requirement on equipment, strong corrosivity, environmental pollution caused by generated waste acid, high post-treatment cost and paradox with green and environment-friendly industrial production; the peroxide added in the epoxidation reaction also has safety risk in large-scale industry, and the excessive peroxide after the reaction needs to be treated by unsaturated sulfide, so that the waste is more and the treatment cost is high.

China developed a new synthetic route from Shanghai combined spice plants in the seventies of the last century. The method also uses pinene as a raw material, firstly pyrolyzes the pinene into alloocimene, then epoxidizes the alloocimene into diepoxide alloocimene, then carries out hydrogenation reaction on an obtained intermediate product, rectifies the intermediate product to obtain alloocimene dihydric alcohol, and finally obtains a target product through selective methoxylation. Due to low yield in pinene cracking, more isomers are obtained: contains myrcene, alloocimene and ocimene, so that the utilization rate of raw materials is low; meanwhile, the use amount of peroxide is larger through double oxidation reaction; the diols after hydrogenation have selectivity problems during methoxylation, which leads to a low overall yield. The whole route has large material loss, high energy consumption and low reaction yield.

Therefore, there is a need in the art to develop a method for preparing santalene with high yield, high conversion rate, simple process and easy industrial production.

Disclosure of Invention

The invention aims to provide a method for preparing sandalwood ether, which has high yield, high conversion rate and simple process and is easy for industrial production.

In a first aspect of the present invention, there is provided a process for the preparation of a santalene ether, said process comprising the steps of:

(i) in an organic solvent, under the action of a hydration catalyst, carrying out hydration reaction on methoxy dihydromyrcene and water to generate sandalwood ether;

wherein the hydration catalyst comprises a first catalyst and a second catalyst;

the first catalyst is a solid acid catalyst, the solid acid catalyst comprises a solid acid and a first metal active component, the first metal active component is loaded on the solid acid, and the first metal active component is selected from the following group: platinum, nickel, molybdenum, or a combination thereof;

the second catalyst comprises a modified cation exchange resin loaded with a second metal active component;

the modified cation exchange resin is subjected to strong acid soaking treatment;

the second metal active component is selected from the group consisting of: zinc chloride, aluminum chloride, tin chloride, ruthenium chloride, rhodium chloride, or combinations thereof.

In another preferred embodiment, the methoxy dihydromyrcene is prepared by the following method:

(ii) under the action of an alcohol synthesis catalyst, reacting dihydromyrcene with methanol to generate methoxy dihydromyrcene;

the catalyst is modified cation exchange resin, and the modified cation exchange resin is cation exchange resin soaked by strong acid.

In another preferred embodiment, in the step (ii), the modified cation exchange resin is the modified cation exchange resin in the step (i).

In another preferred embodiment, in the step (ii), the reaction time is 36-60h, preferably 45-55 h.

In another preferred embodiment, in said step (ii), said reaction temperature is 20-60 ℃, preferably 30-50 ℃.

In another preferred embodiment, in the step (ii), the molar ratio of the dihydromyrcene to the methanol is 1:0.5-8, preferably 1:1-6, and more preferably 1: 2-6.

In another preferred embodiment, in the step (ii), the ratio (g/mol) of the alcohol synthesis catalyst to dihydromyrcene is (5-50g): (0.8-1.2mol), preferably (20-50g): (0.8-1.2mol), more preferably (30-40g): (1 mol).

In another preferred embodiment, in the step (i), the organic solvent is selected from the group consisting of: isopropanol, tetrahydrofuran, acetone, methyltetrahydrofuran, dioxane, acetic acid, acetate, or combinations thereof.

In another preferred embodiment, in the step (i), the reaction time is 3-16h, preferably 3-10 h.

In another preferred embodiment, in said step (i), said reaction temperature is 50-100 ℃, preferably 60-90 ℃, more preferably 70-90 ℃.

In another preferred embodiment, in the step (i), the volume ratio (v/v) of the methoxydihydromyrcene to the water is 1: 0.5-5, preferably 1:0.8-3, more preferably 1: 2-3.

In another preferred embodiment, in the step (i), the volume ratio (v/v) of the organic solvent to the water is 1: 0.5-5, preferably 1:0.8-3, more preferably 1: 0.8-1.2.

In another preferred embodiment, in the step (i), the hydration catalyst is used in an amount of 2 to 20 wt%, preferably 2 to 15 wt%, more preferably 2 to 8 wt%, most preferably 4 to 8 wt% of the amount of the methoxydihydromyrcene.

In another preferred embodiment, the weight percentage of the first metal active component in the solid acid catalyst is 0.5-8 wt%, preferably 1-4 wt%.

In another preferred embodiment, the solid acid catalyst is prepared by a process comprising the steps of:

impregnating a solid acid with a solution of a material selected from the group consisting of: soaking platinic chloride, nickel nitrate hexahydrate, ammonium molybdate tetrahydrate or their mixture, drying and roasting to obtain solid acid catalyst;

the solid acid is selected from the following group: zeolite, silica, alumina, or combinations thereof.

In another preferred embodiment, the solution is an aqueous solution.

In another preferred embodiment, the temperature of drying after impregnation is 100-150 ℃.

In another preferred embodiment, the temperature for the calcination is 400-550 ℃, preferably 450-520 ℃.

In another preferred embodiment, the first metal active component is platinum, nickel and molybdenum.

In another preferred embodiment, the weight percentage of platinum to the solid acid catalyst is 0.1 to 2.5 wt%, preferably 0.1 to 2 wt%, more preferably 0.1 to 1.5 wt%, more preferably 0.2 to 0.8 wt%, most preferably 0.3 to 0.7 wt%.

In another preferred embodiment, the nickel is present in an amount of 0.05 to 1.5 wt%, preferably 0.08 to 1.0 wt%, more preferably 0.08 to 0.5 wt%, and most preferably 0.1 to 0.3 wt% based on the weight of the solid acid catalyst.

In another preferred embodiment, the weight percentage of molybdenum in the solid acid catalyst is 0.05 to 2 wt%, preferably 0.5 to 2 wt%, more preferably 0.8 to 1.5 wt%, and most preferably 1 to 1.5 wt%.

In another preferred embodiment, the solid acid is zeolite.

In another preferred embodiment, the zeolite is selected from the group consisting of: natural zeolite, beta zeolite, Y zeolite, MCM-22, ZSM-5, or a combination thereof.

In another preferred embodiment, the SiO of the β zeolite₂/Al₂O₃(molar ratio) is 20 to 100, preferably 20 to 40, more preferably 20 to 30.

In another preferred embodiment, the beta zeolite is Cation Type H.

In another preferred embodiment, the beta zeolite further has one or more characteristics selected from the group consisting of:

SiO₂/Al₂O₃(molar ratio) of 20 to 100, preferably 20 to 40, more preferably 20 to 30;

the crystallinity is more than or equal to 90 percent, preferably 90 to 98 percent, and more preferably 92 to 97 percent;

the specific surface area is 550-750m²G, preferably 600- & ltwbr/& gt700 m²G, more preferably 620-660m²(ii)/g; and/or

The weight percent of the sodium oxide is less than or equal to 0.1 percent, preferably less than or equal to 0.05 percent, and more preferably 0.01 to 0.05 percent.

In another preferred embodiment, in the second catalyst, the second metal active component is present in an amount of 0.5 to 20 wt%, preferably 1 to 15 wt%, more preferably 2 to 12 wt%, most preferably 4 to 10 wt%, and most preferably 4 to 8 wt% based on the weight of the modified cation exchange resin.

In another preferred embodiment, the zinc chloride is present in the second catalyst in an amount of 0.5 to 20 wt%, preferably 1 to 15 wt%, more preferably 2 to 12 wt%, most preferably 4 to 10 wt%, more preferably 4 to 8 wt% based on the weight of the modified cation exchange resin.

In another preferred embodiment, the weight percentage of the aluminum chloride in the second catalyst is 0.5-20 wt%, preferably 1-15 wt%, more preferably 2-12 wt%, most preferably 4-10 wt%, more preferably 4-8 wt% of the modified cation exchange resin.

In another preferred embodiment, the tin chloride is present in the second catalyst in an amount of 0.5 to 20 wt%, preferably 1 to 15 wt%, more preferably 2 to 12 wt%, most preferably 4 to 10 wt%, more preferably 4 to 8 wt% based on the weight of the modified cation exchange resin.

In another preferred embodiment, the ruthenium chloride is present in the second catalyst in an amount of 0.5 to 20 wt%, preferably 1 to 15 wt%, more preferably 2 to 12 wt%, most preferably 4 to 10 wt%, more preferably 4 to 8 wt% based on the weight of the modified cation exchange resin.

In another preferred embodiment, the weight ratio of the first catalyst to the second catalyst is 0.5-5: 1, preferably 0.5-4:1, more preferably 1-2:1, more preferably 1.2-2:1, more preferably 1.3-1.8: 1.

In another preferred embodiment, the cation exchange resin is a strong acid cation exchange resin.

In another preferred example, the cation exchange resin is a macroporous strong-acid styrene cation exchange resin.

In another preferred example, the functional group of the strong acid cation exchange resin is a sulfonic acid group.

In another preferred embodiment, the cation exchange resin is selected from the group consisting of: d61 macroporous strong acid cation exchange resin (Tianjinbo resin science and technology Co., Ltd.), NKC-9 cation exchange resin, D72 macroporous strong acid cation exchange resin, or a combination thereof.

In another preferred embodiment, the second catalyst is prepared by the following method:

(a) providing a cation exchange resin and a second metal active component;

(b) soaking cation exchange resin in strong acid to obtain modified cation exchange resin;

(c) and mixing the modified cation exchange resin and the second metal active component in an anhydrous solvent, reacting, and filtering to obtain the second catalyst.

In another preferred embodiment, the modified cation exchange resin is prepared by the following method:

(b) soaking cation exchange resin in strong acid to obtain modified cation exchange resin;

in another preferred embodiment, the strong acid is selected from the group consisting of: hydrochloric acid, sulfuric acid, or a combination thereof.

In another preferred embodiment, the concentration of the strong acid is 0.5 to 5mol/L, preferably 1 to 3 mol/L.

In another preferred embodiment, the strong acid is used in an amount of 2 to 20 times, preferably 5 to 15 times, more preferably 8 to 12 times the weight of the cation exchange resin.

In another preferred embodiment, the temperature of said soaking is 20-80 ℃, preferably 30-70 ℃, more preferably 35-45 ℃.

In another preferred embodiment, the soaking time is 2-30h, preferably 5-20h, more preferably 6-16 h.

In another preferred embodiment, the anhydrous solvent is selected from the group consisting of: anhydrous ethanol, anhydrous methanol, anhydrous acetone, or combinations thereof.

In another preferred embodiment, in the step (c), the temperature of the reaction is 60 to 90 ℃, preferably 70 to 90 ℃.

In another preferred embodiment, in the step (c), the reaction time is 3-12h, preferably 4-8 h.

In another preferred embodiment, in the step (c), after the reaction is finished, the reaction mixture is cooled to room temperature (20 ℃) and then filtered.

In another preferred embodiment, in the step (c), after filtration, the second catalyst is obtained after washing with anhydrous ether, acetone and deionized water in sequence and drying (e.g., 75-85 ℃).

In another preferred embodiment, the second catalyst is prepared by the following method:

(a) providing a cation exchange resin and a second metal active component;

(b) soaking cation exchange resin in strong acid for ion exchange, performing modification treatment, and drying to obtain modified cation exchange resin, wherein the concentration of hydrochloric acid is 0.5-5mol/L, the amount of hydrochloric acid is 2-20 times of the weight of the resin, the soaking time is 2-30h, the soaking temperature is 20-80 deg.C, and then drying at 40-80 deg.C;

(c) adding an anhydrous solvent solution of a second metal active component into the modified cation exchange resin, reacting at 60-90 ℃ for 3-12h, cooling to room temperature (20 ℃), filtering, washing with anhydrous ether, acetone and deionized water in sequence, and drying (such as 75-85 ℃) to obtain a second catalyst.

In another preferred embodiment, the modified cation exchange resin is prepared by the following method:

(b) soaking cation exchange resin in strong acid for ion exchange, performing modification treatment, and drying to obtain modified cation exchange resin, wherein the concentration of hydrochloric acid is 0.5-5mol/L, the amount of hydrochloric acid is 2-20 times of the weight of the resin, the soaking time is 2-30h, the soaking temperature is 20-80 deg.C, and then drying at 40-80 deg.C;

in another preferred embodiment, the drying temperature is 55-65 ℃.

In a second aspect of the invention, there is provided a hydration catalyst comprising a first catalyst and a second catalyst;

the first catalyst is a solid acid catalyst, the solid acid catalyst comprises a solid acid and a first metal active component, the first metal active component is loaded on the solid acid, and the first metal active component is selected from the following group: platinum, nickel, molybdenum, or a combination thereof;

the second catalyst comprises a modified cation exchange resin loaded with a second metal active component;

the modified cation exchange resin is subjected to strong acid soaking treatment;

the second metal active component is selected from the group consisting of: zinc chloride, aluminum chloride, tin chloride, ruthenium chloride, rhodium chloride, or combinations thereof.

In another preferred embodiment, the hydration catalyst is a hydration catalyst according to the first aspect of the invention.

It is to be understood that within the scope of the present invention, the above-described features of the present invention and those specifically described below (e.g., in the examples) may be combined with each other to form new or preferred embodiments. Not to be reiterated herein, but to the extent of space.

Drawings

FIG. 1 is a schematic diagram of a rectification apparatus.

Wherein each number in fig. 1 represents: 1.2, 3 is a solvent storage tank; 4. 10, 17, 18, 19 and 20 are heat exchangers; 5. 6, 7, 13, 15 and 23 are delivery pumps; 8. 16, 21 are rectifying towers; 9 is an evaporation kettle; 11 is a reaction tower; 12 a one-way valve; 14 is a continuous layering device; 22 is a sandalwood ether finished product storage tank.

Detailed Description

The invention unexpectedly develops a preparation method of the santalol, which has high yield, high conversion rate, simple process and easy industrial production through extensive research. Experiments show that the solid acid catalyst loaded with platinum, nickel and zeolite and the modified cation exchange resin loaded with the second metal active component can play a synergistic role, so that the selectivity and the methoxy dihydromyrcene conversion rate are remarkably improved.

Term(s) for

As used herein, the terms "comprises," "comprising," "includes," "including," and "including" are used interchangeably and include not only closed-form definitions, but also semi-closed and open-form definitions. In other words, the term includes "consisting of … …", "consisting essentially of … …".

As used herein, "zeolite beta" is also known as molecular sieve beta.

As used herein, "D72 macroporous strong acid cation exchange resin" is a macroporous strong acid styrenic cation exchange resin, also known as D72 macroporous strong acid styrenic cation exchange resin, whose functional group is a sulfonic acid group (-SO 3H).

As used herein. The terms "first catalyst" and "solid acid catalyst" are used interchangeably and include a solid acid and a first metal active component supported on the solid acid, the first metal active component being selected from the group consisting of: platinum, nickel, molybdenum, or a combination thereof.

Preparation method

The invention provides a preparation method of sandalwood ether, which comprises the following steps:

(i) in an organic solvent, under the action of a hydration catalyst, carrying out hydration reaction on methoxy dihydromyrcene and water to generate sandalwood ether;

wherein the hydration catalyst comprises a first catalyst and a second catalyst;

the first catalyst is a solid acid catalyst, the solid acid catalyst comprises a solid acid and a first metal active component, the first metal active component is loaded on the solid acid, and the first metal active component is selected from the following group: platinum, nickel, molybdenum, or a combination thereof;

the second catalyst comprises modified cation exchange resin loaded with a second metal active component, and the modified cation exchange resin is subjected to strong acid soaking treatment;

the second metal active component is selected from the group consisting of: zinc chloride, aluminum chloride, tin chloride, ruthenium chloride, rhodium chloride, or combinations thereof.

In a preferred embodiment of the present invention, the methoxy dihydromyrcene is prepared by the following method:

(ii) under the action of an alcohol synthesis catalyst, reacting dihydromyrcene with methanol to generate methoxy dihydromyrcene;

the catalyst is modified cation exchange resin, and the modified cation exchange resin is cation exchange resin soaked by strong acid.

In a preferred embodiment of the present invention, in the step (i), the organic solvent is selected from the group consisting of: isopropanol, tetrahydrofuran, acetone, methyltetrahydrofuran, dioxane, acetic acid, acetate, or combinations thereof.

In another preferred embodiment, in the step (i), the reaction time is 3-16h, preferably 3-10 h.

In another preferred embodiment, in said step (i), said reaction temperature is 50-100 ℃, preferably 60-90 ℃, more preferably 70-90 ℃.

In another preferred embodiment, in the step (i), the volume ratio (v/v) of the methoxydihydromyrcene to the water is 1: 0.5-5, preferably 1:0.8-3, more preferably 1: 2-3.

In another preferred embodiment, in the step (i), the volume ratio (v/v) of the organic solvent to the water is 1: 0.5-5, preferably 1:0.8-3, more preferably 1: 0.8-1.2.

In another preferred embodiment, in the step (i), the hydration catalyst is used in an amount of 2 to 20 wt%, preferably 2 to 15 wt%, more preferably 2 to 8 wt%, most preferably 4 to 8 wt% of the amount of the methoxydihydromyrcene.

In another preferred embodiment, the weight percentage of the first metal active component in the solid acid catalyst is 0.5-8 wt.%, preferably 1-4 wt.%.

In the method for preparing the sandalwood ether, the raw material methoxy dihydromyrcene has double bonds, and hydroxyl groups can be connected with different carbon atoms of the double bonds in hydration reaction, so that various hydration reaction products (namely, different carbon atoms of the double bonds are connected with the hydroxyl groups) can be generated.

In the method for preparing the sandalwood ether of the present invention, the selectivity (%) refers to the percentage of the sandalwood ether produced by the reaction to the amount of the substance of the product produced by the reaction (including the product formed by connecting different carbon atoms of the double bond and the hydroxyl group), for example, in the method for preparing the sandalwood ether of the present invention, 100mol of the product is produced, wherein 90mol of the sandalwood ether is produced, and the selectivity is 90%.

In the method for producing a sandalwood ether of the present invention, the conversion (%) is calculated as the conversion of methoxydihydromyrcene. For example, 100g of methoxydihydromyrcene is used as a raw material, 60g of methoxydihydromyrcene participates in the reaction, and the conversion (%) is 60% of the methoxydihydromyrcene (60g) participating in the reaction to the charged methoxydihydromyrcene (100 g).

In the invention, methoxy dihydromyrcene has a hydration reaction with water under the action of a hydration catalyst, and then the sandalwood ether is obtained by rectification and purification.

Modified cation exchange resin

In the invention, the modified cation exchange resin is cation exchange resin soaked by strong acid.

In a preferred embodiment of the present invention, the cation exchange resin is a strongly acidic cation exchange resin.

In another preferred example, the cation exchange resin is a macroporous strong-acid styrene cation exchange resin.

In another preferred example, the functional group of the strong acid cation exchange resin is a sulfonic acid group.

In another preferred embodiment, the cation exchange resin is selected from the group consisting of: d61 macroporous strong acid cation exchange resin (Tianjinbo resin science and technology Co., Ltd.), NKC-9 cation exchange resin, D72 macroporous strong acid cation exchange resin, or a combination thereof.

Alcohol synthesis catalyst

In the present invention, the alcohol synthesizing catalyst is preferably a modified cation exchange resin.

Hydration catalyst

In the preparation method of the sandalwood ether, under the action of a hydration catalyst, methoxy dihydromyrcene and water are subjected to hydration reaction to generate the sandalwood ether.

Typically, the hydration catalyst includes a first catalyst and a second catalyst.

First catalyst

In the present invention, the first catalyst is a solid acid catalyst, the solid acid catalyst comprises a solid acid and a first metal active component, the first metal active component is supported on the solid acid, and the first metal active component is selected from the following group: platinum, nickel, molybdenum, or a combination thereof.

In a preferred embodiment of the present invention, the weight percentage of the first metal active component in the solid acid catalyst is 0.5-8 wt.%, preferably 1-4 wt.%.

In another preferred embodiment, the solid acid catalyst is prepared by a process comprising the steps of:

impregnating a solid acid with a solid acid carrier selected from the group consisting of: soaking platinic chloride, nickel nitrate hexahydrate, ammonium molybdate tetrahydrate or their mixture, drying and roasting to obtain solid acid catalyst;

the solid acid is selected from the following group: zeolite, silica, alumina, or combinations thereof.

In another preferred embodiment, the temperature of drying after impregnation is 100-150 ℃.

In another preferred embodiment, the temperature for the calcination is 400-550 ℃, preferably 450-520 ℃.

Preferably, the platinum is present in an amount of 0.1 to 2.5 wt%, preferably 0.1 to 2 wt%, more preferably 0.1 to 1.5 wt%, more preferably 0.2 to 0.8 wt%, and most preferably 0.3 to 0.7 wt% based on the weight of the solid acid catalyst.

Preferably, the nickel is present in an amount of 0.05 to 1.5 wt%, preferably 0.08 to 1.0 wt%, more preferably 0.08 to 0.5 wt%, and most preferably 0.1 to 0.3 wt% based on the weight of the solid acid catalyst.

Preferably, the molybdenum is present in an amount of 0.05 to 2 wt%, preferably 0.5 to 2 wt%, more preferably 0.8 to 1.5 wt%, and most preferably 1 to 1.5 wt% based on the weight of the solid acid catalyst.

In another preferred embodiment, the solid acid is zeolite.

In another preferred embodiment, the zeolite is selected from the group consisting of: natural zeolite, beta zeolite, Y zeolite, MCM-22, ZSM-5, or a combination thereof.

In another preferred embodiment, the zeolite beta has a SiO2/Al2O3 (molar ratio) of 20 to 100, preferably 20 to 40, more preferably 20 to 30.

In another preferred embodiment, the beta zeolite is Cation Type H.

In another preferred embodiment, the beta zeolite further has one or more characteristics selected from the group consisting of:

SiO2/Al2O3 (molar ratio) is 20 to 100, preferably 20 to 40, more preferably 20 to 30;

the crystallinity is more than or equal to 90 percent, preferably 90 to 98 percent, and more preferably 92 to 97 percent;

the specific surface area is 550-750m2/g, preferably 600-700m2/g, more preferably 620-660m 2/g; and/or

The wt.% of sodium oxide is less than or equal to 0.1%, preferably less than or equal to 0.05%, more preferably 0.01-0.05%.

In another preferred embodiment, in the second catalyst, the second metal active component is present in an amount of 0.5 to 20 wt%, preferably 1 to 15 wt%, more preferably 2 to 12 wt%, most preferably 4 to 10 wt%, and most preferably 4 to 8 wt% based on the weight of the modified cation exchange resin.

Second catalyst

In the invention, the second catalyst comprises a modified cation exchange resin loaded with a second metal active component, the modified cation exchange resin is a cation exchange resin soaked by strong acid, and the second metal active component is selected from the following group: zinc chloride, aluminum chloride, tin chloride, ruthenium chloride, rhodium chloride, or combinations thereof.

In a preferred embodiment of the present invention, in the second catalyst, the second metal active component accounts for 0.5-20 wt%, preferably 1-15 wt%, more preferably 2-12 wt%, most preferably 4-10 wt%, and most preferably 4-8 wt% of the modified cation exchange resin.

Preferably, the weight percentage of the zinc chloride in the second catalyst to the modified cation exchange resin is 0.5 to 20 wt%, preferably 1 to 15 wt%, more preferably 2 to 12 wt%, most preferably 4 to 10 wt%, more preferably 4 to 8 wt%.

Preferably, in the second catalyst, the aluminum chloride accounts for 0.5-20 wt%, preferably 1-15 wt%, more preferably 2-12 wt%, most preferably 4-10 wt%, more preferably 4-8 wt% of the modified cation exchange resin.

Preferably, in the second catalyst, the tin chloride is present in an amount of 0.5 to 20 wt%, preferably 1 to 15 wt%, more preferably 2 to 12 wt%, most preferably 4 to 10 wt%, more preferably 4 to 8 wt% based on the weight of the modified cation exchange resin.

Preferably, the ruthenium chloride is present in the second catalyst in an amount of 0.5 to 20 wt%, preferably 1 to 15 wt%, more preferably 2 to 12 wt%, most preferably 4 to 10 wt%, more preferably 4 to 8 wt%, based on the weight of the modified cation exchange resin.

In another preferred embodiment, the second catalyst is prepared by the following method:

(a) providing a cation exchange resin and a second metal active component;

(b) soaking cation exchange resin in strong acid to obtain modified cation exchange resin;

(c) and mixing the modified cation exchange resin and the second metal active component in an anhydrous solvent, reacting, and filtering to obtain the second catalyst.

In another preferred embodiment, the anhydrous solvent is selected from the group consisting of: anhydrous ethanol, anhydrous methanol, anhydrous acetone, or combinations thereof.

In another preferred embodiment, in the step (c), the temperature of the reaction is 60 to 90 ℃, preferably 70 to 90 ℃.

In another preferred embodiment, in the step (c), the reaction time is 3-12h, preferably 4-8 h.

In another preferred embodiment, in the step (c), after the reaction is finished, the reaction mixture is cooled to room temperature (20 ℃) and then filtered.

In another preferred embodiment, in the step (c), after filtration, the second catalyst is obtained after washing with anhydrous ether, acetone and deionized water in sequence and drying (e.g., 75-85 ℃).

The main excellent technical effects obtained by the invention comprise:

the invention unexpectedly develops a method for preparing the sandalwood ether, the method has excellent technical effects of high selectivity, high yield, high conversion rate and the like, and the method for preparing the sandalwood ether by a one-step hydration method has simple process and is suitable for industrial production.

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out under conventional conditions or conditions recommended by the manufacturers. Unless otherwise indicated, percentages and parts are by weight.