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Production method of 4, 6-dihydroxypyrimidine

A technology of dihydroxypyrimidine and a production method, which is applied in the production field of 4,6-dihydroxypyrimidine, can solve the problems of inability to further increase the product content, increase the difficulty of methanol treatment, increase the consumption of raw material formamide, etc., and solve the problem of waste water generation. large amount, reducing the difficulty of post-treatment of wastewater, good economic and social benefits

Active Publication Date: 2021-09-28
潍坊滨海石油化工有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the production of ammonia gas, there are the following disadvantages in both processes: (1) The ammonia content in the methanol evaporated after the reaction is about 1.5%, and further pressurized distillation is required to obtain ammonia-free methanol, which increases the methanol (2) The generation of ammonia comes from the decomposition of materials after adding formamide under the reaction conditions, which increases the consumption of raw material formamide; (3) The by-product ammonia causes the ammonia of dimethyl malonate solution, malonate diamide is generated, resulting in the formation of nicotinamide ring-forming impurities. The content of commercial 4,6-dihydroxypyrimidine products is about 98%, and the content of the product cannot be further increased

Method used

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  • Production method of 4, 6-dihydroxypyrimidine
  • Production method of 4, 6-dihydroxypyrimidine
  • Production method of 4, 6-dihydroxypyrimidine

Examples

Experimental program
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Effect test

Embodiment 1

[0042] (1) Cyclization reaction: Add 12600kg of methanol solution containing 30%wt sodium methoxide to a 20000L reactor, then concentrate until the sodium methoxide content is 38%wt, cool down, then add formamide 2172kg, methyl formate 76kg, Close the vent valve of the reactor, heat up to 60°C, then add 2627kg dimethyl malonate, control the reaction temperature at 60-65°C, and the reaction pressure is 0.01MPa, heat preservation and pressure preservation (use the pressure in the reactor after the temperature rise to maintain pressure) to react for 6 hours;

[0043] (2) Cool down and dissolve: cool down to 30°C, add 8930kg of water, stir for 2 hours to dissolve 4,6-dihydroxypyrimidine sodium salt;

[0044] (3) Alcohol distillation under reduced pressure: continuously add the fully dissolved reaction solution into the rectification tower, control the temperature of the tower to 40-50°C, recover anhydrous methanol from the top of the tower, and continuously discharge the 4,6-disti...

Embodiment 2

[0048] (1) Cyclization reaction: Add 12600kg of methanol solution containing 30%wt sodium methoxide to a 20000L reactor, then concentrate until the sodium methoxide content is 40%wt, cool down, then add formamide 2170kg, methyl formate 72kg, Close the vent valve of the reaction kettle, heat up to 65°C, then add 2640kg dimethyl malonate, control the reaction temperature at 65-70°C, and the reaction pressure is 0.03MPa, heat preservation and pressure maintenance (use the pressure in the reaction kettle after the temperature rise to maintain pressure) to react for 5 hours;

[0049] (2) Cool down and dissolve: cool down to 32°C, add 8980kg of water, stir for 1 hour to dissolve 4,6-dihydroxypyrimidine sodium salt;

[0050] (3) Alcohol distillation under reduced pressure: continuously add the fully dissolved reaction solution into the rectification tower, control the temperature of the tower kettle at 50-60°C, recover anhydrous methanol from the top of the tower, and continuously di...

Embodiment 3

[0054](1) Cyclization reaction: Add 12600kg of methanol solution containing 30%wt sodium methoxide to a 20000L reactor, then concentrate until the sodium methoxide content is 36%wt, cool down, then add formamide 2170kg, methyl formate 68kg, Maintain the normal pressure of the reactor, raise the temperature to 70°C, and then add 2635kg of dimethyl malonate, control the reaction temperature at 70-75°C, and the reaction pressure is 0.3MPa (filled with dry nitrogen to maintain the pressure), and keep the temperature for 4 hours;

[0055] (2) Cool down and dissolve: cool down to 35°C, add 8960kg of water, stir for 1 hour to dissolve 4,6-dihydroxypyrimidine sodium salt;

[0056] (3) Alcohol distillation under reduced pressure: continuously add the fully dissolved reaction solution into the rectification tower, control the temperature of the tower kettle at 60-70°C, recover anhydrous methanol from the top of the tower, and continuously discharge the 4,6-distillate from the tower kettl...

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Abstract

The invention belongs to the technical field of synthesis of 4, 6-dihydroxypyrimidine, and particularly relates to a production method of 4, 6-dihydroxypyrimidine, which comprises the following steps: a, performing cyclization reaction; b, cooling and dissolving; c, distilling alcohol under reduced pressure; d, performing acidification and separation; and e, washing and drying. The method provided by the invention not only improves the product content and yield, but also reduces the content of ammonia gas in recovered methanol, ensures the smooth proceeding of the main reaction, reduces the consumption of raw materials, solves the problems of large wastewater generation amount and difficult wastewater treatment, and has good economic and social benefits.

Description

technical field [0001] The invention belongs to the technical field of 4,6-dihydroxypyrimidine synthesis, and specifically relates to a production method of 4,6-dihydroxypyrimidine. Background technique [0002] As a synthetic intermediate, 4,6-dihydroxypyrimidine is mainly used in the production of sulfa drugs, and is also the main intermediate for the preparation of the fungicide azoxystrobin, with a large market demand. [0003] At present, 4,6-dihydroxypyrimidine is generally produced by the reaction of dimethyl malonate, formamide, and sodium methoxide in industry. After the reaction is completed, part of the methanol is removed, and water is added to dissolve it. After removing impurities with activated carbon , and then add mineral acid to precipitate 4,6-dihydroxypyrimidine, and the precipitated solid is washed with water and dried to obtain the product. [0004] The production process is divided into normal pressure method (CN1105110C) and pressurized method (CN122...

Claims

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Application Information

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IPC IPC(8): C07D239/54
CPCC07D239/54
Inventor 王丽窦荣坦王龙富杨文涛张均盈周成伟李茂春刘娟
Owner 潍坊滨海石油化工有限公司
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