Catalyst for preparing 1,2-dimethylimidazole and preparation method thereof

A technology of dimethylimidazole and catalyst, which is applied in the field of preparation of solid acid catalytic materials, can solve the problem of low yield of 1,2-dimethylimidazole, complex catalyst preparation method, high yield of 1,2-dimethylimidazole, etc. problems, to achieve the effect of rich acid content, short preparation time and uniform grain size

Active Publication Date: 2021-07-27
YANCHENG INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] Purpose of the invention: The present invention aims at the problems of complex catalyst preparation method and low yield of 1,2-dimethylimidazole in the current preparation process of 1,2-dimethylimidazole, and provides a method for synthesizing 1,2-dimethylimidazole The preparation method of the catalyst of imidazole, the preparation method of the catalyst is simple, and the yield of 1,2-dimethylimidazole is high

Method used

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  • Catalyst for preparing 1,2-dimethylimidazole and preparation method thereof
  • Catalyst for preparing 1,2-dimethylimidazole and preparation method thereof
  • Catalyst for preparing 1,2-dimethylimidazole and preparation method thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0025] With 9.52g chromium nitrate (consumption is represented by Cr 2 o 3 Calculation), 8.5g ammonia water (dosage is expressed as NH 3 Calculation), 44.1g tetraethylammonium hydroxide (TEAOH), 72g deionized water, the molar ratio is Cr 2 o 3 :NH 3 :TEAOH:H 2 O=1:25:15:200 mixed, at room temperature with a stirring rate of 80r / min stirring for 3h, to obtain the first solution; according to SnO 2 :Cr 2 o 3 =1:1 molar ratio, with 5.34g sodium stannate (consumption is based on SnO 2 Calculation) and 21.6g deionized water, in molar ratio for SnO 2 :H 2 O=1:60 mixing, stirring at room temperature at a stirring rate of 80r / min for 1h to obtain the second solution; adding the second solution dropwise to the first solution at a rate of 1.5mL / min, at a temperature of 60°C Stir at a stirring rate of 80r / min for 1h to form a sol-gel; transfer the sol-gel into a supercritical reactor, and feed carbon dioxide gas into the reactor to make the reactor reach a supercritical tempera...

Embodiment 2

[0027] With 10.64g chromium chloride (consumption is represented by Cr 2 o 3 Calculation), 10.2g ammonia water (dosage is expressed as NH 3 Calculation), 81.2g tetrapropyl ammonium hydroxide (TPAOH), 90g deionized water, the molar ratio is Cr 2 o 3 :NH 3 :TPAOH:H 2 O=1:30:20:250 mixing, stirring at room temperature at a stirring rate of 120r / min for 1h to obtain the first solution; press SnO 2 :Cr 2 o 3 =1:4 molar ratio, with 0.95g stannous chloride (consumption is based on SnO 2 Calculation) and 9.0g deionized water, in molar ratio for SnO 2 :H 2 O=1:100 mixing, stirring at room temperature at a stirring rate of 100r / min for 1h to obtain the second solution; adding the second solution dropwise to the first solution at a rate of 2.0mL / min, at a temperature of 80°C Stir at a stirring rate of 120r / min for 3 hours to form a sol-gel; transfer the sol-gel into a supercritical reactor, and feed carbon dioxide gas into the reactor to make the reactor reach a supercritical t...

Embodiment 3

[0029] With 10.64g chromium chloride (consumption is represented by Cr 2 o 3 Calculation), 9.52g ammonia water (dosage is expressed as NH 3 Calculation), 93.24g tetrabutylammonium hydroxide (TBAOH), 79.2g deionized water, Cr 2 o 3 :NH 3 :TBAOH:H 2 O=1:28:18:220 mixed, at room temperature with a stirring rate of 100r / min stirring for 3h, to get the first solution; according to SnO 2 :Cr 2 o 3 =1:2 molar ratio, with 2.67g sodium stannate (consumption is based on SnO 2 Calculation) and 14.4g deionized water, in molar ratio for SnO 2 :H 2 O=1:80 mixing, stirring at room temperature at a stirring rate of 100r / min for 3h to obtain the second solution; adding the second solution dropwise to the first solution at a rate of 1.8mL / min, at 90°C Stir at a stirring rate of 100r / min for 3 hours to form a sol-gel; transfer the sol-gel into a supercritical reactor, and feed carbon dioxide gas into the reactor to make the reactor reach a supercritical temperature of 100°C and a press...

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Abstract

The invention discloses a catalyst for preparing 1,2-dimethylimidazole and a preparation method thereof. The preparation method comprises the following steps: uniformly mixing a chromium source, ammonia water, a structure-directing agent and deionized water under stirring at the room temperature so as to obtain a first solution; mixing a tin source with deionized water, and conducting uniform stirring at room temperature to obtain a second solution; dropwise adding the second solution into the first solution, and performing stirring at a temperature of 60-90 DEG C to form sol-gel; transferring the obtained sol-gel into a supercritical reaction kettle for a crystallization reaction; and filtering an obtained crystallization product, washing and drying the crystallization product, and conducting roasting at 450 DEG C for 1-3 hours to obtain the product. The catalyst is small in grain size, large in specific surface area, large in the number of exposed acid active sites, rich in acid amount, high in acid strength and beneficial for dehydration reactions of 2-methylimidazole and methanol, and the raw material conversion rate and the yield of the target product 1,2-dimethylimidazole are high.

Description

technical field [0001] The invention belongs to the technical field of preparation of solid acid catalytic materials, in particular to a catalyst for catalyzing the dehydration reaction of 2-methylimidazole and methanol to prepare 1,2-dimethylimidazole and a preparation method thereof. Background technique [0002] 1,2-Dimethylimidazole is an important pharmaceutical intermediate, which can also be used as a curing agent for epoxy resins and other resins, and is widely used in epoxy resin bonding, encapsulation, impregnation, etc. In the Chinese invention patent CN 104402823 B, bisimidazole is first prepared by aminoacetaldehyde diethyl acetal, succinamide and 2,4-dimethylbenzoic acid, and then 1,2-dimethylimidazole is obtained from bisimidazole. The reaction process of this technology is relatively cumbersome, resulting in a low final yield of 1,2-dimethylimidazole; and a large amount of solvents such as nitric acid and chloroform are used in the process, resulting in waste...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J23/26B01J35/00B01J35/02B01J35/10B01J37/03C07D233/58
CPCB01J23/002B01J23/26B01J35/023B01J35/1019B01J35/1023B01J35/0013B01J37/036B01J37/031C07D233/58Y02P20/54
Inventor 丁建飞沈健
Owner YANCHENG INST OF TECH
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