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A kind of method for preparing 4-dimethylaminopyridine

A technology of dimethylaminopyridine and cyanopyridine, which is applied in the chemical industry, can solve the problems of unsatisfactory recycling effect, hindering industrial application, and high price of 2-vinylpyridine, so as to facilitate mass transfer and reaction and improve product selection properties, the effect of reducing water content

Active Publication Date: 2021-07-23
杭州瑞思新材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the price of 2-vinylpyridine used in this method is high, and the recycling effect is not ideal, which hinders industrial application

Method used

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  • A kind of method for preparing 4-dimethylaminopyridine

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] (1) Put 1.1 mol of acrylic acid raw material into the reaction kettle, put into concentrated hydrochloric acid raw material (the molar number of hydrogen chloride is 2.2 mol), put into the polymerization inhibitor hydroquinone 0.0055 mol, heat up and stir. The reaction was stirred at a temperature of 80°C for 4 hours.

[0030] (2) At a temperature of 80° C., slowly add 1.0 mol of 4-cyanopyridine raw material for 2 hours. After the addition is completed, continue the reaction for 2 hours. Excess hydrochloric acid was recovered by distillation under reduced pressure.

[0031] (3) The above-mentioned reaction solution obtained is slowly added dropwise to 40% aqueous dimethylamine solution (the molar number of dimethylamine is 2.0mol) under the condition of heat preservation at 80°C, the reaction temperature is controlled at reflux at 50°C, and the dropwise addition time is controlled The reaction was incubated for 1 hour followed by an incubation period of 1 hour.

[003...

Embodiment 2

[0038] (1) Put 1.3mol of acrylic acid raw material into the reaction kettle, put into concentrated hydrochloric acid raw material (the molar number of hydrogen chloride is 3.3mol), put into 0.0065mol of polymerization inhibitor hydroquinone, heat up and stir. The reaction was stirred at a temperature of 100°C for 2 hours.

[0039] (2) At a temperature of 100° C., slowly add 1.0 mol of 4-cyanopyridine raw material for 1 hour. After the addition is complete, continue the reaction for 1 hour. Excess hydrochloric acid was recovered by distillation under reduced pressure.

[0040] (3) The above-mentioned reaction solution obtained is slowly added dropwise to 40% aqueous solution of dimethylamine (the molar number of dimethylamine is 4.0mol) under the condition of heat preservation at 100° C. At 2 hours, followed by a 2 hour incubation reaction.

[0041] (4) At a temperature of 70° C., slowly add liquid caustic soda raw material (50% in mass concentration, 6.0 mol of sodium hydroxid...

Embodiment 3

[0047] (1) Put 1.2 mol of acrylic acid raw material into the reaction kettle, put into concentrated hydrochloric acid raw material (the molar number of hydrogen chloride is 2.5 mol), put into 0.006 mol of polymerization inhibitor hydroquinone, heat up and stir. The reaction was stirred at a temperature of 90°C for 3 hours.

[0048] (2) Slowly add 1.0 mol of 4-cyanopyridine raw material at a temperature of 90° C. for 1.5 hours. After the addition is complete, continue the reaction for 1.5 hours. Excess hydrochloric acid was recovered by distillation under reduced pressure.

[0049] (3) The above-mentioned reaction solution obtained is slowly added dropwise to 40% aqueous dimethylamine solution (the molar number of dimethylamine is 3.0mol) under the condition of heat preservation at 90° C. At 1.5 hours, followed by a 1.5 hour incubation reaction.

[0050] (4) At a temperature of 60° C., slowly add liquid caustic soda raw material (mass concentration 40%, sodium hydroxide molar...

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Abstract

The present invention discloses a new method for preparing 4-dimethylaminopyridine, which includes putting acrylic acid raw materials into a reaction kettle, putting in concentrated hydrochloric acid raw materials, putting in hydroquinone, raising the temperature and stirring, and stirring and reacting at a temperature of 80-100°C 2‑4 hours; at a temperature of 80‑100 ° C, slowly add 4‑cyanopyridine raw materials for 1‑2 hours, after the addition is complete, continue to react for 1‑2 hours, and recover excess hydrochloric acid by vacuum distillation Steps, according to the reaction mechanism and reaction kinetics, the present invention first reacts acrylic acid raw materials with cheap hydrochloric acid raw materials, thereby avoiding the reaction probability of acrylic acid after hydrochloric acid is directly salted with 4-cyanopyridine. In the present invention, acrylic acid has been fully activated so that sufficient group protection reactions can occur with 4-cyanopyridine. At the same time, hydroquinone is used as a polymerization inhibitor of acrylic acid to ensure that other side reactions do not occur at high temperatures.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a novel method for preparing 4-dimethylaminopyridine. Background technique [0002] 4-Dimethylaminopyridine is a new high-efficiency catalyst widely used in chemical synthesis, white crystalline powder, molecular formula C 7 h 10 N 2 . The molecular structure is as follows: [0003] [0004] 4-Dimethylaminopyridine (DMAP), CAS Accession No. 1122-58-3. [0005] 4-Dimethylaminopyridine is a new type of high-efficiency catalyst widely used in chemical synthesis in recent years. The electron-donating dimethylamino in its structure resonates with the parent ring (pyridine ring), which can strongly activate the nitrogen atom on the ring for nucleophilic substitution. , significantly catalyzes the acylation (phosphorylation, sulfonylation, carbonylation) of alcohols and amines with high steric hindrance and low reactivity, and its activity is about 10 times that of pyr...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D213/74
CPCC07D213/74
Inventor 张治国颜吉校张富成
Owner 杭州瑞思新材料有限公司