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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AI-Extracted 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...
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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.

Application Domain

Organic chemistry

Technology Topic

ChemistryPyrimidine +8

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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(5)
  • Comparison scheme(1)

Example Embodiment

[0041] Example 1
[0042] (1) Cycling Reaction: The methanol solution of 30% WT methoxide was 12600 kg of a meta-wt of sodium, then concentrated to a 20000L reactor, and then concentrated to a methoxide content of 38% wt, cooling, then adding formamide 2172 kg, methyl formate 76 kg, Turn off the reactor vacuum valve, warmed to 60 ° C, then add 2627 kg of dimethyl malonate, control the reaction temperature at 60-65 ° C, the reaction pressure is 0.01 MPa, the insulation pressure (after the temperature of the reaction, the reactive kettle Pressure) reaction for 6 hours;
[0043] (2) Cooling and dissolution: Cooling to 30 ° C, 8930 kg of water, stirred for 2 hours, dissolve 4,6-dihydroxypatine sodium salt;
[0044] (3) Decutation steaming alcohol: Continuissly dissolved reaction liquid continuously added to the distillation column, control the tower temperature 40-50 ° C, recovering aerobic alcohol from the top of the column, from the tower, continuously discharged 4, 6- 2 Solution of hydroxypydenidine sodium salts;
[0045] (4) Acidification and separation: 1,28% WT hydroxylated acid is added to the pH of 2-3, precipitated 4,6-dihydroxypyrimidine. Centrifugal filtration, 4,6-dihydroxypyrimidine solid wet materials and filtered filtrate;
[0046] (5) Wash dry: Wash the 4,6-dihydroxypyrimidine solid wet material with deionized water, dry, 4,6-dihydroxypyrimidine solid products 2124.6 kg, yield 95.5%, and the content is 99.72%.

Example Embodiment

[0047] Example 2
[0048] (1) Cycling reaction: The methanol solution of 30% WT methoxide was 12600 kg of a methanol of 5,200 l, then concentrated to a 20000L reactor, and then concentrated to a sodium methanol content of 40% wt, cooling, then adding formamide 2170 kg, methyl formate 72 kg, Turn off the reactor vacuum valve, warmed to 65 ° C, then add 2640 kg of dimethyl malonate, control the reaction temperature at 65-70 ° C, reaction pressure is 0.03 MPa, insulation preservation (using the temperature of the reaction kettle) Pressure) reaction for 5 hours;
[0049] (2) Cooling and dissolution: Cooling to 32 ° C, 8980 kg of water is added, stirring for 1 hour, 4,6-dihydroxypatine sodium salt is dissolved;
[0050] (3) Decutant steam: The sufficiently dissolved reaction solution is continuously added to the distillation column, control the tower temperature 50-60 ° C, recover aeroanol from the top of the tower, from the tower, continuously discharged 4, 6- 2 Solution of hydroxypydenidine sodium salts;
[0051] (4) Acidification and separation: 1,28% WT hydroxylated acid is added to the pH of 2-3, precipitated 4,6-dihydroxypyrimidine. Centrifugal filtration, 4,6-dihydroxypyrimidine solid wet materials and filtered filtrate;
[0052] (5) Wash dry: Wash the 4,6-dihydroxypyrimidine solid wet material with deionized water, dry, 4,6-dihydroxypyrimidine solid products 2141.5 kg, yield 95.8%, and the content is 99.80%.

Example Embodiment

[0053] Example 3
[0054](1) Cycling reaction: The methanol solution of 30% WT methoxide was 12600 kg of a meta-wt of sodium, then concentrated to a 20000L reactor, and then concentrated to a sodium methanol content of 36% wt, cooling, then adding formamide 2170 kg, methyl formate 68kg, The reaction kettle was maintained at normal pressure, warmed to 70 ° C, and then added 2635 kg of dimethyl group of malonate, the control reaction temperature was 70-75 ° C, the reaction pressure was 0.3 MPa (filled nitrogen pressure), and the insulation reaction was 4 hours;
[0055] (2) Cooling and dissolution: Cooling to 35 ° C, 8960 kg of water was added, and the mixture was dissolved for 4,6-dihydroxypatine sodium salt;
[0056] (3) Decutation steam: The sufficiently dissolved reaction solution is continuously added in the distillation column, control the tower temperature of 60-70 ° C, recovering anhydrous methanol from the top of the tower, from the tower, continuously discharged 4, 6- 2 Solution of hydroxypydenidine sodium salts;
[0057] (4) Acidification and separation: Add 30% WT hydrochloric acid to a solution of 4,6-dihydroxypatostile sodium salts discharged to pH to 2-3, precipitated 4,6-dihydroxypyrimidine, centrifuge Filtration, 4,6-dihydroxypyrimidine solid wet materials and filtered filtrate;
[0058] (5) Wash dry: Wash the 4,6-dihydroxypylamyin solid wet material with deionized water, dry, 4,6-dihydroxypyridine solid products 2124.2 kg, yield 95.2%, and the content is 99.58%.

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