Clean nitration reaction of aromatic hydrocarbon of heteropolyacid pyridinium ionic liquid catalyst

Abstract

The invention discloses a novel method for clean nitration reaction of aromatic hydrocarbon of heteropolyacid pyridinium ionic liquid catalyst. The used catalyst is ionic liquid in which negative ions are heteropolyacid radicals and positive ions are pyridinium structures; the raw materials are aromatic hydrocarbon compound and nitric acid; and the aromatic hydrocarbon nitration product is obtained by nitration reaction under the effect of the catalyst. Compared with the prior art, the invention has the advantages that: (1) the ionic liquid of heteropolyacid negative ion structure is employed, the raw material source is wide and the preparation process is convenient; and the reaction is stable for water, and the catalyst will not lose effectiveness and can be circularly used; (2) the heteropolyacid pyridinium ionic liquid catalyst has high activity and low usage amount and is convenient to recover; and (3) the ionic liquid is used to replace concentrated sulfuric acid used in nitric acid / sulfuric acid mixing technology, and the method is safe, reliable and environment-friendly, and has industrial application prospect.

Description

a technical field

[0001] The invention relates to a new method for catalyzing the clean nitration reaction of aromatic hydrocarbons by a heteropolyacid pyridinium salt ionic liquid, and belongs to the technical field of chemical material preparation. This method is suitable for the occasion of synthesizing aromatic hydrocarbon nitration products with aromatic compound and nitric acid as raw materials by heating and stirring under normal pressure. Two background technology

[0002] The nitration reaction of aromatic compounds is an important organic synthesis unit reaction, and substituted aromatic hydrocarbon nitrates are a very important class of chemical products. Both academia and industry have carried out research on the methods and processes of nitration reactions of aromatic compounds. The process adopts the nitric-sulfur mixed acid nitration method that has been used in the past for a hundred years to carry out the nitrification reaction. This method has the disadvant...

Examples

Embodiment 1

[0021] In a 25mL round bottom flask, add 10mmol (1.81g) p-chlorobenzotrifluoride, 30mmol (2.8g) 68% nitric acid, 1mmol catalyst (anion is H 2 PMo 12 o 40 - ), mixed and stirred for 5 hours at 80° C., cooled, and stood to separate the phases. The crude product in the upper layer was washed with water, neutralized and dried in vacuum to obtain the pure product 4-chloro-3-nitrobenzotrifluoride, with a yield of 85%.

Embodiment 2

[0023] In a 25mL round bottom flask, add 10mmol (1.81g) p-chlorobenzotrifluoride, 30mmol (2.8g) 68% nitric acid, 1mmol catalyst (anion is H 2 PW 12 o 40 - ), mixed and stirred for 5 hours at 80° C., cooled, left to stand for phase separation, and the crude product in the upper layer was washed with water, neutralized, and vacuum-dried to obtain the pure product 4-chloro-3-nitrobenzotrifluoride, with a yield of 83%.

Embodiment 3

[0025] In a 25mL round bottom flask, add 10mmol (1.81g) p-chlorobenzotrifluoride, 30mmol (2.8g) 68% nitric acid, 1mmol catalyst (anion is H 2 SiW 12 o 40 - ), mixed and stirred for 5 hours at 80° C., cooled, and stood to separate the phases. The crude product in the upper layer was washed with water, neutralized and dried in vacuum to obtain the pure product 4-chloro-3-nitrobenzotrifluoride, with a yield of 84%.

a technical field

[0001] The invention relates to a new method for catalyzing the clean nitration reaction of aromatic hydrocarbons by a heteropolyacid pyridinium salt ionic liquid, and belongs to the technical field of chemical material preparation. This method is suitable for the occasion of synthesizing aromatic hydrocarbon nitration products with aromatic compound and nitric acid as raw materials by heating and stirring under normal pressure. Two background technology

[0002] The nitration reaction of aromatic compounds is an important organic synthesis unit reaction, and substituted aromatic hydrocarbon nitrates are a very important class of chemical products. Both academia and industry have carried out research on the methods and processes of nitration reactions of aromatic compounds. The process adopts the nitric-sulfur mixed acid nitration method that has been used in the past for a hundred years to carry out the nitrification reaction. This method has the disadvant...

Examples

Embodiment 1

[0021] In a 25mL round bottom flask, add 10mmol (1.81g) p-chlorobenzotrifluoride, 30mmol (2.8g) 68% nitric acid, 1mmol catalyst (anion is H 2 PMo 12 o 40 - ), mixed and stirred for 5 hours at 80° C., cooled, and stood to separate the phases. The crude product in the upper layer was washed with water, neutralized and dried in vacuum to obtain the pure product 4-chloro-3-nitrobenzotrifluoride, with a yield of 85%.

Embodiment 2

[0023] In a 25mL round bottom flask, add 10mmol (1.81g) p-chlorobenzotrifluoride, 30mmol (2.8g) 68% nitric acid, 1mmol catalyst (anion is H 2 PW 12 o 40 - ), mixed and stirred for 5 hours at 80° C., cooled, left to stand for phase separation, and the crude product in the upper layer was washed with water, neutralized, and vacuum-dried to obtain the pure product 4-chloro-3-nitrobenzotrifluoride, with a yield of 83%.

Embodiment 3

[0025] In a 25mL round bottom flask, add 10mmol (1.81g) p-chlorobenzotrifluoride, 30mmol (2.8g) 68% nitric acid, 1mmol catalyst (anion is H 2 SiW 12 o 40 - ), mixed and stirred for 5 hours at 80° C., cooled, and stood to separate the phases. The crude product in the upper layer was washed with water, neutralized and dried in vacuum to obtain the pure product 4-chloro-3-nitrobenzotrifluoride, with a yield of 84%.

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