A kind of preparation method of 2,5-disubstituted-1,4-terephthalaldehyde

A technology of terephthalaldehyde and disubstitution, which is applied in the field of organic synthesis, can solve the problems of cumbersome post-processing, low yield, and difficult to obtain products, and achieve the effects of increasing reaction yield, improving reaction activity, and improving efficiency

Active Publication Date: 2022-05-03
NINGBO POLYTECHNIC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the existing synthetic methods, the product is difficult to obtain, the post-treatment is cumbersome and the yield is very low

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Design reaction route:

[0031] Weigh 5g of raw materials (19mmol) and 0.17g, 0.95mmol of hexamethylphosphoric triamide (HMPA), put them into a 500mL three-necked bottle with a built-in thermometer, and after vacuuming for 3 times, place in a dry ice ethanol bath, and control the temperature- At 78°C, 2.1 equiv of tert-butyllithium (39.9 mmol, 30.69 mL, 1.3 M / L) was added dropwise, and the addition was completed in 1 hour. Slowly rise to room temperature, and continue stirring at room temperature for 20 min. Then reset the reaction system in a dry ice ethanol bath, keep warm at -78°C, and slowly add 13.89 g of DMF dropwise into the system. After the dropwise addition, remove the dry ice ethanol bath, and stir at room temperature for 50 min. Under ice bath, add 40 mL of saturated ammonium chloride aqueous solution dropwise to the reaction system to quench; extract with ethyl acetate twice, wash the organic phase twice with saturated brine, dry the organic phase, conce...

Embodiment 2

[0033] The design reaction route is:

[0034] Weigh 5.5g of raw materials (19mmol) and 0.17g, 0.95mmol of hexamethylphosphoric triamide (HMPA), put them into a 500mL three-necked bottle with a built-in thermometer, and after vacuuming for 3 times, place in a dry ice ethanol bath and control the temperature At -79°C, 2.1 equiv of tert-butyllithium (39.9 mmol, 30.69 mL, 1.3 M / L) was added dropwise, and the addition was completed in 1 hour. Slowly rise to room temperature, and continue stirring at room temperature for 30 min. The reaction system was then reset in a dry ice ethanol bath, kept at -79°C, and 13.89 g of DMF was slowly added dropwise into the system. After the dropwise addition, the dry ice ethanol bath was removed, and stirred at room temperature for 60 min. Under ice bath, add 50 mL of saturated ammonium chloride aqueous solution dropwise to the reaction system to quench; extract with ethyl acetate 3 times, wash the organic phase with saturated brine 3 times, dry...

Embodiment 3

[0036] Design reaction route:

[0037] Weigh 6.15g of raw materials (19mmol) and 0.068g, 0.38mmol of hexamethylphosphoric triamide (HMPA), put them into a 500mL three-necked bottle with a built-in thermometer, and after 3 times of vacuum ventilation, place in a dry ice ethanol bath and control the temperature At -80°C, 2.1 equiv of tert-butyllithium (39.9 mmol, 30.69 mL, 1.3 M / L) was added dropwise, and the addition was completed in 1 hour. Slowly rise to room temperature, and continue stirring at room temperature for 40 min. Then reset the reaction system in a dry ice ethanol bath, keep warm at -80°C, and slowly add 16.64 g of DMF dropwise into the system. After the dropwise addition, remove the dry ice ethanol bath, and stir at room temperature for 70 min. Under ice bath, add 60 mL of saturated ammonium chloride aqueous solution dropwise to the reaction system to quench; extract with ethyl acetate 4 times, wash the organic phase with saturated brine 4 times, dry the organ...

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PUM

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Abstract

The invention belongs to the technical field of organic synthesis, and specifically relates to a preparation method of 2,5-disubstituted-1,4-terephthalaldehyde. 2,5-disubstituted-1,4-terephthalaldehyde of the present invention is made of 2,5-disubstituted-1,4-dibromobenzene and DMF in hexamethylphosphoric triamide (HMPA) and tert-butyllithium It is produced under the catalytic action of oxidation reaction. Adding tert-butyllithium to the reaction system greatly improves the reaction activity, and with the help of a small amount of HMPA, the existence form of carbocations is stabilized. When tert-butyllithium and HMPA work together, the reaction yield is greatly improved, both at 78 % and above, greatly improving the efficiency of product quantification.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a preparation method of 2,5-disubstituted-1,4-terephthalaldehyde. Background technique [0002] 2,5-disubstituted-1,4-terephthalaldehyde is widely used as a photoelectric material. Most of the existing technologies use 2,5-disubstituted-1,4-dibromobenzene as raw material. Synthesis of 2,5-disubstituted-1,4 dialdehyde benzene by extracting halogen. However, in the existing synthetic methods, the product is difficult to obtain, the post-treatment is cumbersome and the yield is very low. Literature reports Miao Z, Liu G, Cui Y, et al.NovelStrategy for Construction of Covalent Organic Frameworks Transformed from Nonporous Covalent Organic Polymers[J].Angewandte Chemie, 2019, 131(15):4960-4964 using 4 equivalents of n-butyllithium, Yield is only 13%; Literature report P, Wessig, M, et al.Molecular RodsBased on Oligo-spiro-thioketals[J].The Journal of Organic Ch...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C45/00C07C45/27C07C47/544C07C47/575
CPCC07C45/00C07C45/27C07C47/544C07C47/575
Inventor 陈艳君史海波
Owner NINGBO POLYTECHNIC
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