CN114230435A

CN114230435A - Preparation method of octachloronaphthalene

Info

Publication number: CN114230435A
Application number: CN202111618108.3A
Authority: CN
Inventors: 于龙; 张�杰; 周丽娜; 郭钦; 武翰
Original assignee: Shandong Boyuan Pharmaceutical Chemical Co ltd
Current assignee: Shandong Boyuan Pharmaceutical Chemical Co ltd
Priority date: 2021-12-27
Filing date: 2021-12-27
Publication date: 2022-03-25
Anticipated expiration: 2041-12-27
Also published as: CN114230435B

Abstract

The invention discloses a preparation method of octachloronaphthalene, which comprises the steps of taking 2-naphthol as a raw material, introducing chlorine gas into a solvent for chlorination, introducing nitrogen gas after chlorine introduction to effectively replace residual chlorine gas, adding a chlorination reagent into a system for continuous heating reaction, cooling for crystallization after the reaction is finished, and filtering to separate a product. The preparation method designed by the invention has the advantages of no side reaction, no need of catalyst, quick reaction, high product content, no need of refining and the like.

Description

Preparation method of octachloronaphthalene

Technical Field

The invention relates to the field of chemical industry, in particular to a preparation method of octachloronaphthalene.

Background

Octachloronaphthalene, named as 1,2,3,4,5,6,7, 8-Octachloronaphthalene, named as "perchloronaphthalene", CAS No. 2234-13-1, is an octachloride of naphthalene, has good chemical stability and thermal stability, is used as an insulating material in the electrical industry, an additive for a grinding wheel medium and a cutting oil coolant, and is also used for synthesizing a bactericide and an algicide. Regarding the preparation of octachloronaphthalene, the synthesis method reported in chinese patent CN101844964A is: in an organic solvent, naphthalene is reacted at the temperature of 60-130 ℃ under the action of a metal catalyst by introducing chlorine gas, the amount of the chlorine gas is 8.0-10.0 times of that of the naphthalene, the reaction time is 6-24 hours, and after the reaction is finished, the reaction solution is subjected to post-treatment to obtain octachloronaphthalene; the metal catalyst is iron or zinc; the organic solvent is carbon tetrachloride, tetrachloroethane or tetrachloroethylene. However, the technology has the problems of long reaction time and low yield, the verification shows that the by-product with the decachloronaphthalene is difficult to control, and the crude product needs to be refined to meet the purity requirement.

Decachloronaphthalene:

decachloro-1,4-dihydronaphthaleneperchloro-1,4-dihydronaphthalenedecachloro-1,4-dihydro-naphthaleneDecachlor-1,4-dihydro-naphthalin1,2,3,4,5,5,6,7,8,8-Decachlor-5,8-dihydro-naphthalinOctachlornaphthalin-1,4-dichlorid

CAS：14396-29-3

disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a preparation method of octachloronaphthalene, which has the advantages of no need of a catalyst, quick reaction, no side reaction, high product content and no need of refining.

The invention is realized by the following steps: the method comprises the following steps of taking 2-naphthol as a raw material, introducing chlorine gas into a solvent for chlorination, introducing nitrogen gas after the chlorine introduction is finished to effectively replace residual chlorine gas, adding a chlorination reagent into a system for continuous heating reaction, cooling for crystallization after the reaction is finished, and separating a product by filtering.

The method specifically comprises the following steps:

(1) and (3) chlorine introducing stage: adding a solvent and 2-naphthol into a reaction vessel, heating to a reaction temperature, and introducing chlorine for reaction;

(2) hydroxyl chloride band stage: introducing nitrogen into the reaction container after chlorine introduction is finished, effectively replacing residual chlorine, adding a chlorinated reagent, heating to the reaction temperature for reaction, and tracking by HPLC until the reaction is complete;

(3) and after the reaction is finished, cooling to room temperature, and filtering and separating precipitated solids to obtain the product.

The method comprises the following more specific steps:

(1) and (3) chlorine introducing stage: adding a solvent and 2-naphthol into a reaction bottle, connecting a ventilation device, a stirring device, a condenser pipe, a thermometer, a safety bottle and a tail gas absorption device, heating in an oil bath to a reaction temperature, and starting ventilation reaction;

(2) hydroxyl chloride band stage: and (3) introducing nitrogen into the reaction bottle after chlorine introduction is finished to effectively replace residual chlorine, adding a chlorinated reagent, heating to the reaction temperature for reaction, and tracking by HPLC until the reaction is complete.

(3) And (3) cooling to room temperature after the reaction is finished, separating out a large amount of solids, and filtering and separating to obtain the product. Recrystallization solvent is not needed for recrystallization, catalyst is not needed, and decachloronaphthalene by-product is not generated.

The solvent in the step (1) is one or a mixture of dichloroethane, carbon tetrachloride, chloroform, tetrachloroethylene, tetrachloroethane and the like; the adding amount of the solvent is 2-15 times of the mass of the naphthol.

The reaction temperature in the step (1) is 60-150 ℃; the reaction time is 4-12 h.

The chlorinated reagent in the step (2) is one or a mixture of more of phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride and the like, and the addition amount of the chlorinated reagent is 1-3 times of the amount of the naphthol substance.

The reaction temperature in the step (2) is 60-150 ℃; HPLC traces to completion, typically for a reaction time of 1-4 h.

The excellent effects of the invention are as follows:

(1) no side reaction; in the prior art, naphthalene is taken as a raw material and chlorine is introduced to prepare octachloronaphthalene, and when an octachloronaphthalene product reaches a certain amount along with the chlorine introduction reaction, an intermediate which is not chlorinated still exists on a naphthalene ring, and the continuous introduction of chlorine gas can cause a decachloronaphthalene side reaction of a product which further reacts with chlorine, and cannot be controlled. The key factor of the side reaction is the coexistence of a large amount of products and intermediates, but the new route designed by the invention finally generates heptachloronaphthol in the chlorine introducing process, and no octachloronaphthalene product is generated, so that the side reaction of decachloronaphthalene is controlled from the source. The reaction of heptachloronaphthol and chlorinated reagent produces octachloronaphthalene product with hydroxyl chloride, and although octachloronaphthalene product is produced in great amount, no chlorine gas produces environment and no decachloronaphthalene side reaction occurs.

(2) Compared with the prior art, the catalyst is not needed, and the cost is low;

(3) the reaction is rapid;

(4) the product has high content and no need of refining.

Detailed Description

The advantageous effects of the present invention will now be further described by the following examples, which should be understood as being for illustrative purposes only and not limiting the scope of the present invention, and that changes and modifications apparent to those of ordinary skill in the art in light of the present invention are also included within the scope of the present invention.

Example 1

(1) And (3) chlorine introducing stage: 173g of dichloroethane and 57.67g (0.4mol) of 2-naphthol are added into a reaction bottle, and the reaction bottle is connected with aeration equipment, a stirring device, a condenser tube, a thermometer, a safety bottle and a tail gas absorption device, and after the temperature of oil bath is raised to 85 ℃, 200g (2.8mol) of gas starts to be aerated for reaction for 8 hours;

(2) hydroxyl chloride band stage: and (3) introducing nitrogen into the reaction bottle after chlorine introduction to effectively replace residual chlorine, adding 125g (0.6mol) of phosphorus pentachloride with the mass being 1 time that of 2-naphthol, heating to 90 ℃, and tracking by HPLC (high performance liquid chromatography) until the reaction is complete.

(3) After the reaction is finished, the temperature is reduced to room temperature, a large amount of solid is separated out, and the product 148.56g is obtained after filtration and separation.

The yield was 92% and the HPLC content was 99.1%.

Example 2

(1) And (3) chlorine introducing stage: adding 865g of chloroform and 57.67g (0.4mol) of 2-naphthol into a reaction bottle, connecting an aeration device, a stirring device, a condensing tube, a thermometer, a safety bottle and a tail gas absorption device, heating in an oil bath to 70 ℃, and then introducing 285g (4mol) of gas to react for 6 hours;

(2) hydroxyl chloride band stage: and (3) introducing nitrogen into the reaction bottle after chlorine introduction to effectively replace residual chlorine, adding 164.8g (1.2mol) of phosphorus trichloride with the mass being 3 times that of 2-naphthol, heating to 70 ℃, and tracking by HPLC (high performance liquid chromatography) until the reaction is complete.

(3) After the reaction is finished, the temperature is reduced to room temperature, a large amount of solid is separated out, and the product 145.33g is obtained after filtration and separation.

The yield was 90% and the HPLC content was 99.2%.

Example 3

(1) And (3) chlorine introducing stage: 460g of tetrachloroethylene and 57.67g (0.4mol) of 2-naphthol are added into a reaction bottle, and the reaction bottle is connected with a ventilation device, a stirring device, a condenser tube, a thermometer, a safety bottle and a tail gas absorption device, and 227g of air is introduced into the reaction bottle for reaction for 4 hours after the temperature of an oil bath is raised to 120 ℃;

(2) hydroxyl chloride band stage: and (3) introducing nitrogen into the reaction bottle after chlorine introduction to effectively replace residual chlorine, adding 92g (0.6mol) of phosphorus oxychloride with the mass being 1.5 times that of 2-naphthol, heating to 130 ℃, and tracking by HPLC until the reaction is complete.

(3) After the reaction is finished, the temperature is reduced to room temperature, a large amount of solid is separated out, and 153.4g of the product is obtained after filtration and separation.

The yield was 95% and the HPLC content was 99%.

Example 4

(1) And (3) chlorine introducing stage: adding 500g of carbon tetrachloride and 57.67g (0.4mol) of 2-naphthol into a reaction bottle, connecting a ventilation device, a stirring device, a condenser tube, a thermometer, a safety bottle and a tail gas absorption device, raising the temperature of an oil bath to 80 ℃, and then starting ventilation for 200g to react for 12 hours;

(2) hydroxyl chloride band stage: and (3) introducing nitrogen into the reaction bottle after chlorine introduction to effectively replace residual chlorine, adding 125g (0.6mol) of phosphorus pentachloride with the mass being 1.5 times that of 2-naphthol, heating to 90 ℃, and tracking by HPLC until the reaction is complete.

(3) After the reaction is finished, the temperature is reduced to room temperature, a large amount of solid is separated out, and the product 143.72g is obtained after filtration and separation.

The yield was 89%, and the HPLC content was 99.4%.

It should be understood that the above experimental examples are only examples for clearly illustrating the present invention, and are not intended to limit the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A preparation method of octachloronaphthalene comprises the following steps:

2. The preparation method according to claim 1, wherein the solvent in step (1) is one or more selected from dichloroethane, carbon tetrachloride, chloroform, tetrachloroethylene and tetrachloroethane.

3. The preparation method according to claim 1, wherein the solvent in the step (1) is added in an amount of 2 to 15 times the mass of 2-naphthol; the amount of chlorine introduced is 7-10 times of that of naphthol.

4. The method for preparing the compound of claim 1, wherein the reaction temperature in the step (1) is 60-150 ℃; the reaction time is 4-12 h.

5. The preparation method of claim 1, wherein the chlorinating reagent in step (2) is one or more of phosphorus trichloride, phosphorus pentachloride and phosphorus oxychloride.

6. The method according to claim 1, wherein the chlorinated reagent is added in an amount of 1 to 3 times the amount of the naphthol compound.

7. The method for preparing the compound of claim 1, wherein the reaction temperature in the step (2) is 60-150 ℃; the reaction time is 1-4 h.

8. The production method according to claim 1, wherein the temperature is raised by an oil bath.