CN1224709A

CN1224709A - Improved tricarbonyl chloride synthesizing process and its application

Info

Publication number: CN1224709A
Application number: CN 98120179
Authority: CN
Inventors: 石铭兆; 陈家骏; 杨学敏; 王素娜
Original assignee: Tianjin City No7 Dye Chemical Plant
Current assignee: Tianjin City No7 Dye Chemical Plant
Priority date: 1998-10-23
Filing date: 1998-10-23
Publication date: 1999-08-04

Abstract

The synthesis of triphosgene is implemented by adopting main reactor and auxiliary reactor to make reaction at 20-60 deg.C and 20-30 deg.C respectively under the condition of illumination. Then the obtained triphosgene is diazotized with diazo component, condensed and coupled so as to obtain the dyestuff. Said invention is high in triphosgene yield, quick in reaction speed, less in chlorine gas consumption, and its intermediate step for synthesizing dyestuff is easy to control, after-treatment procedure can be reduced, and its cost is low.

Description

Improvement and utilization of triphosgene synthesis process

The invention relates to improvement and utilization of a triphosgene synthesis process.

Triphosgene, i.e., bis (trichloromethyl) carbonate, is also known as solid phosgene. It is a stable solid crystal, is extremely safe in the process of transportation, storage and use, and is only used for replacing virulent phosgene when being treated by common toxicants.

Trichloromethyl carbonate is produced by chlorination of dimethyl carbonate, and it has been proposed to use trichloromethyl carbonate as an alternative to phosgene for organic synthesis as early as 1987, and many studies have been made on this problem. It has been successfully used in many fields such as organic synthesis, agricultural chemicals, medicines, high molecular materials and dye synthesis.

In the synthesis process of triphosgene, an Ecker method is adopted at home and abroad, namely: adding dimethyl carbonate into carbon tetrachloride solvent, performing chlorine introduction reaction at 10-20 ℃ under illumination, and then distilling to obtain solid dimethyl carbonate, wherein the yield is 97%, and the melting point is 79 ℃. The method has the advantages of low reaction speed, high chlorine consumption and low yield.

The existing phosgene synthetic dye production process has two methods: 1. coupling diazo component and coupling component, then condensing with phosgene; 2. introducing phosgene into a coupling component for condensation to form a dye intermediate, and then forming a dye with a diazo component. However, the amount of phosgene introduced is 2-5 times the theoretical amount, so that impurities are easily formed, the color of the dye is dark, the strength is low, and excessive phosgene needs to be treated, thereby causing waste and environmental pollution. The domestic report on the production of dye by triphosgene is synthesized by the method 1; the diazo component and the coupling component are coupled to form a colored fore dye, and the dye is condensed by adding triphosgene after treatment. Its advantages are no need of phosgene, and no need of post-treating step and apparatus. The deficiency is that the dye needs to be treated before synthesis; the product cost is high.

The invention aims to provide improvement and utilization of a triphosgene synthesis process, which changes the synthesis reaction of triphosgene into a secondary reaction and effectively improves the reaction speed and yield; the syntheticdye has low consumption, easy control of intermediate steps and simple operation.

The technical scheme of the invention is realized as follows: the improvement of the triphosgene synthesis process is that carbon tetrachloride and dimethyl carbonate are filled into a 500ml four-mouth bottle main reactor which is provided with a thermometer, a chlorine introducing pipe, a condenser and a stirrer, and the weight ratio of the carbon tetrachloride to the dimethyl carbonate is 100: 10-15. The outlet of the condenser of the main reactor was introduced via a conduit into a 500ml sub-reactor equipped with a thermometer condenser (which absorbed unreacted chlorine and a little uncondensed solvent). Adding materials into the secondary reactor according to the charging amount of the main reactor, keeping the reaction temperature of the main reactor at 20-60 ℃, keeping the secondary reactor at 20-30 ℃, introducing chlorine gas under illumination to react until the materials in the main reactor do not change color any more, cooling, crystallizing, drying, and mechanically using mother liquor to obtain the triphosgene finished product. Pouring the material of the secondary reactor into the main reactor, drying, pouring the mother liquor into the secondary reactor, adding dimethyl carbonate, and repeating the above reaction. The reaction formula is as follows:

Uv、CCl₄O

the triphosgene is synthesized by adding quantitative triphosgene as the coupling component and condensing. Diazotizing the diazo component, directly synthesizing the dye with the coupling component, and salting out, filtering, and drying to obtain the standardized dye. The general reaction formula is as follows:

1. diazo: in the formula: Ar-NH₂__ aromatic primary amine compound

X __ acid radical, e.g. Cl^-、SO₄ ⁼Etc.; 2. Condensation: o2 Ar' -NH₂+1/3CCl3OCOCCl₃+2NaOH

O

→Ar’NHCHNAr’

In the formula: ar' __ phenols and arylamine compounds;

3. coupling: o is

2Ar-N₂X+Ar’NHCHNAr’→

O

Ar-N=N-Ar’NHCHNAr’-N=N-Ar

The invention has the advantages that: the main reactor and the secondary reactor are adopted, so that the recovery rate of the product is high, the speed is high, and the chlorine consumption is low; the triphosgene prepared by the method has simple operation, easy control of the intermediate steps for synthesizing the dye, reduction of the pre-dye and the intermediate post-treatment process and lower cost.

The synthesis process and the utilization example of triphosgene are as follows:

example 1. carbon tetrachloride 300ml and dimethyl carbonate 52 g were charged into each of a main reactor and a sub-reactor equipped with a thermometer, a vent pipe, a condenser and a stirrer (the sub-reactor does not require stirring), and the sub-reactor received unreacted chlorine gas and an uncondensed solvent in the main reactor in a liquid state through the condenser and a pipe of the main reactor. Keeping the temperature of the main reactor at 20-60 ℃, keeping the temperature of the secondary reactor at 20-30 ℃, introducing chlorine gas into the main reactor under the condition of illumination, stirring until the color of materials in the main reactor is notchanged, and cooling, crystallizing and drying; 170 g of colorless granular crystals were obtained in a yield of 99% at mp.79 ℃. Pouring the residual materials in the secondary reactor into the main reactor, pouring the mother liquor after being dried into the secondary reactor, adding dimethyl carbonate according to the above-mentioned mixing ratio, repeating the above-mentioned reaction so as to obtain new colorless granular crystal-solid triphosgene.

The reaction formula in the synthesis process is as follows:

Uv、CCl₄O

then using the obtained solid triphosgene to directly carry out orange S synthesis (C, I, Di-rect orange 26); diazotization in the first step: adding 80ml of water into a 500ml beaker, adding 14ml of 30% hydrochloric acid, adding ice to reduce the temperature to 0-2 ℃, adding 4.7 g (0.05mol) of industrial aniline, stirring for 15 minutes, adding 11.5 g of 30% sodium nitrite solution, keeping the sodium nitrite in slight excess and reacting for 30 minutes, wherein the reaction formula is as follows:

and (2) second-step condensation: 150ml of water was added to a 1000ml beaker, 11.95 g (0.05mol) of 100% of a mesoacid was added, the pH =7 was adjusted by adding sodium carbonate, 3.4 g of triphosgene was added, the temperature was maintained at 20-40 ℃ and the pH =6.5-7 for 6 hours of reaction, the end points were: the content of the mesoacid is less than or equal to 1 percent. The reaction formula is as follows: ,

2Ar’-NH₂+1/3CCl₃OCOCCl₃+2NaOH

O

→ Ar ' NHCHNAR 'Ar ' __ phenols and arylamines.

The third step of coupling: and (3) adding sodium carbonate into the condensation liquid to adjust the pH to be between 9 and 10, adding ice and cooling to 4 to 6 ℃. Adding diazo solution, and reacting at 10-15 deg.C and pH =7-7.5 for 3 hr. Adding 6-8% of salt for salting out, filtering, drying to obtain 61.1 g of standardized dye.

Example 2 triphosgene synthesis the same as example 1. Then directly carrying out acid-resistant scarlet 4BS synthesis. Diazotization in the first step: 50ml of water was added to a 500ml beaker, 14ml of 30% hydrochloric acid was added, ice was added thereto and the temperature was lowered to 0 ℃ and 3.83 g (0.0255mol) of p-aminoacetanilide and 2.28 g (0.0245mol) of aniline were added. Adding 11.5 g of 30 percent sodium nitrite solution at the temperature of 0-5 ℃, and keeping the sodium nitrite in slight excess for reaction for 30 minutes. The reaction scheme is the same as example 1. The step 2 and the step three are the same as the example 1, and finally the standardized dye 41 yuan is obtained.

Dyes that may also be applicable using the triphosgene co-obtained with 2 above include: C. i, direct orange 26, 29, 72, 102, 108, etc.; C. i, direct yellow 26, 31, 44, 50, 52, 117, 118, 120, etc.; C. i, direct red 4, 14, 23, 24, 36, 54, 72, 80, 83, 89, 98, 99, 122, 162, 176, etc.; C. i, direct violet 103, etc.; c. I, direct brown 112, etc.

Claims

1. An improvement and utilization of triphosgene synthesis process is characterized in that the improvement mode is that carbon tetrachloride and dimethyl carbonate are filled in a 500ml four-mouth bottle main reactor which is provided with a thermometer, a chlorine introducing pipe, a condenser and a stirrer, and the weight ratio of the carbon tetrachloride to the dimethyl carbonate is 100: 10-15. The outlet of the condenser of the main reactor was introduced via a conduit into a 500ml sub-reactor equipped with a thermometer condenser (which absorbed unreacted chlorine and a little uncondensed solvent). Adding materials into the secondary reactor according to the charging amount of the main reactor, keeping the reaction temperature of the main reactor at 20-60 ℃, keeping the secondary reactor at 20-30 ℃, introducing chlorine gas under illumination to react until the materials in the main reactor do not change color any more, cooling, crystallizing, drying, and mechanically using mother liquor to obtain the triphosgene finished product. Pouring the material of the secondary reactor into the main reactor, drying, pouring the mother liquor into the secondary reactor, adding dimethyl carbonate, and repeating the above reaction. The reaction formula is as follows: uv, CCl₄O

2. The improvement and utilization of the triphosgene synthesis process of claim 1, wherein the triphosgene synthesis is carried out by adding the coupling component to a predetermined amount of triphosgene, condensing, and then directly using the condensed triphosgene as the coupling component without any treatment. Diazotizing the diazo component, directly synthesizing the dye with the coupling component, and salting out, filtering, and drying to obtain the standardized dye. The general reaction formula is as follows: (1) diazo: in the formula: Ar-NH₂__ aromatic primary amine compound

X __ acid radical, e.g. Cl^-、SO₄ ⁼Etc.; (2) condensation: o2 Ar' -NH₂+1/3CCl₃OCOCl₃+2NaOH

O

→Ar’NHCHNAr’In the formula: ar' __ phenols and arylamine compounds; (3) coupling: o2Ar-N₂X+Ar’NHCHNAr’→

OAr-N=N-Ar’NHCHNAr’-N=N-Ar