Green preparation technique of 1,4-diiodo-benzene

A technology of diiodobenzene and p-iodoaniline, which is applied in the field of green preparation technology of 1,4-diiodobenzene, can solve the problems of large amount of hydroiodic acid, insufficient reaction, high reaction cost, etc., and achieve high product purity and reduce Production cost, simplification of operation engineering effect

Active Publication Date: 2016-06-15
WUHAN INSTITUTE OF TECHNOLOGY
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  • Abstract
  • Description
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Problems solved by technology

Since the freezing point of acetic acid is 16.6°C, it is easy to solidify during low-temperature diazotization, resulting in insufficient reaction
In addit...

Method used

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  • Green preparation technique of 1,4-diiodo-benzene
  • Green preparation technique of 1,4-diiodo-benzene
  • Green preparation technique of 1,4-diiodo-benzene

Examples

Experimental program
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Effect test

Embodiment 1

[0033] Such as figure 1 Process flow: Add 9.3g of aniline (0.1mol) to 110ml of 10% (w / w) potassium bicarbonate solution, then add crushed iodine to aniline molar ratio of 1.05:1 within 15 to 20 minutes 26.7g of elemental iodine was subjected to electrophilic substitution reaction at 5-10°C for 4 hours, and filtered after the reaction was completed. The liquid is the potassium iodide solution generated by the reaction, which is directly used for the iodine displacement reaction. After the solid was dried, 21.0 g of p-iodoaniline was obtained with a yield of 95.8%. Such as figure 2 , proton nuclear magnetic resonance spectrum analysis result: 1 HNMR (CDCl3, 270MHz), 7.40(d, 2H), 6.47(d, 2H), 3.38(s, 2H), nuclear magnetic resonance test showed that it was the target product.

[0034] Add 21.0g of p-iodoaniline (0.096mol) into 400 ml of water, control the reaction temperature below 0°C, add 90 ml of 36.5% (w / w) concentrated hydrochloric acid with a molar ratio of hydrochloric...

Embodiment 2

[0037] Add 13.95 g of aniline (0.15 mol) to 110 ml of 15% (w / w) potassium bicarbonate solution, then add 40.0 g of crushed iodine to aniline with a molar ratio of 1.05:1 in batches within 15 to 20 minutes Elemental iodine, carry out electrophilic substitution reaction at 5-10°C for 4 hours, and filter after the reaction is completed. The liquid is the potassium iodide solution generated by the reaction, which is directly used for the iodine displacement reaction. After the solid was dried, 31.1 g of p-iodoaniline crude product was obtained, with a yield of 94.5%, which was shown to be the target product by nuclear magnetic resonance.

[0038] 31.1g p-iodoaniline (0.142mol) is added to 600 milliliters of water, control reaction temperature is less than 0 ℃, add sulfuric acid and p-iodoaniline mol ratio is 5.25: 1 the concentrated sulfuric acid of 40.5 milliliters 98% (w / w), quick Cool to -10°C to precipitate ultra-fine white crystals, then add dropwise 50 ml of 20% (w / w) sodiu...

Embodiment 3

[0041] 1.86kg aniline (20mol) was added to 20 liters of 10% (w / w) potassium bicarbonate solution, then within 40 minutes, 5.34kg elemental iodine ( 21mol), the electrophilic substitution reaction was carried out at 5-10°C for 6 hours, and filtered after the reaction was completed. The liquid is the potassium iodide solution generated by the reaction, which is directly used for the iodine displacement reaction. After the solid was dried, 4.07 kg of p-iodoaniline was obtained, and the nuclear magnetic resonance test showed that it was the target product with a yield of 93.0%.

[0042] Add 4.07kg of p-iodoaniline (18.6mol) into 80 liters of water, control the reaction temperature to be less than 0°C, add 20 liters of 36.5% (w / w) concentrated hydrochloric acid with a molar ratio of hydrochloric acid to p-iodoaniline of 12.8:1, and quickly cool Precipitate ultra-fine white crystals at -10°C, then add dropwise 6.6 liters of 20% (w / w) sodium nitrite solution with a molar ratio of so...

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Abstract

The invention relates to a green preparation technique of 1,4-diiodo-benzene. The technique comprises the following steps: carrying out electrophilic substitution reaction on a simple substance iodine and aniline in a weakly alkaline medium solution, separating, and drying to obtain a paraiodoaniline crude product; carrying out diazo-reaction on the paraiodoaniline crude product and a sodium nitrate solution to prepare a diazonium salt, and removing excess sodium nitrate in the system; adding chloroform and a potassium iodide solution into the reaction system, reacting for 3-6 hours while keeping the temperature at -5 to -10 DEG C, slowly heating to room temperature, continuing reacting for 2-6 hours, and carrying out separation and purification on the reaction product to obtain the 1,4-diiodo-benzene. The technique has the advantage of high product purity, and obviously lowers the production cost. The technique implements comprehensive utilization of the potassium iodide waste solution resources, thereby lowering the production cost. The technique simplifies the operation engineering, and enhances the yield of the product.

Description

technical field [0001] The invention relates to a green preparation process of 1,4-diiodobenzene. Background technique [0002] 1,4-Diiodobenzene is an important organic intermediate, which reacts with different active groups to synthesize a variety of substituted functional group compounds. It is widely used in the fields of medicine, pesticides and materials, and its synthesis and application are of great research value. [0003] There are many ways to synthesize 1,4-diiodobenzene, among which the diazotization iodination method of arylamine is a relatively common method. These methods are mainly divided into the following categories. [0004] Diazotization of p-phenylenediamine hydrochloride, followed by displacement reaction with potassium iodide, the amino group of diphenylamine is replaced by iodine to obtain 1,4-diiodobenzene. Since the raw material p-phenylenediamine has been diazotized twice, the diazotization yield is low; in addition, the content of 4-chlorobenz...

Claims

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Application Information

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IPC IPC(8): C07C17/093C07C25/02C07C209/74C07C211/52C07C245/20
CPCC07C17/093C07C209/74C07C245/20C07C25/02C07C211/52
Inventor 汪锋王迅昶李昱达李辉程畅
Owner WUHAN INSTITUTE OF TECHNOLOGY
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