Preparation method of triazine ring

A technology of triazine ring and methyl thiosemicarbazide, applied in directions such as organic chemistry, can solve problems such as high cost, complicated process, inconvenient operation, etc., and achieve the effects of easy recovery and processing, cheap and easy-to-obtain raw materials, and avoiding difficulty in recovery.

Active Publication Date: 2021-05-07
SHANDONG JINCHENG KERUI CHEMICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The route of this process is more complicated, especially the preparation of raw material methylmalonyl chloride is complicated, and the yield is low (about 80%), and it is a highly active acid chloride intermediate, which is inconvenient to operate, and it must use ion exchange resin simultaneously. Purification, complex process, high cost, not suitable for industrial production, no practical production significance
[0009] In order to avoid these two disadvantages, the patent CN 104177305 A proposes the idea of ​​using a mixed solvent, but this invention introduces one of DMF, DMSO, NMP, HMPA, acetone, acetonitrile, dioxane, and THF. None of the solvents are in the reaction system. The biggest disadvantage of the above patents is the introduction of a new solvent system, which increases the difficulty of recycling and introduces new environmental issues.

Method used

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  • Preparation method of triazine ring
  • Preparation method of triazine ring

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Experimental program
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Effect test

Embodiment 1

[0036] Add 10.5 g of 2-methylthiosemicarbazide, 15.3 g of diethyl oxalate, 31.5 g of methanol, and 31.5 g of ethanol to the reaction flask, drop to 15° C., dropwise add a mixed alkali catalyst (including 36.8 g of sodium methoxide, 0.05 g of DMAP, TMEDA 0.05g) for 1.5h, after the dropwise addition, the temperature was raised to 55°C for cyclization reaction for 2.5h, acidified with hydrochloric acid to pH=1.0, cooled to 5°C and suction filtered to obtain a crude triazine ring. The crude product was dissolved in 63g of distilled water at 70°C and cooled down. Crystallization at 15°C, suction filtration to obtain a triazine ring wet product, and drying at 100°C for 3 hours to obtain 14.75 g of a triazine ring dry product with a purity of 99.6% and a yield of 92.7%.

Embodiment 2

[0038] Add 10.5 g of 2-methylthiosemicarbazide, 16.1 g of diethyl oxalate, 15.8 g of methanol, and 36.8 g of ethanol to the reaction flask, drop to 5°C, and dropwise add a mixed alkali catalyst (including 26.3 g of sodium methoxide, 0.01 g of DMAP, TMEDA 0.01g) 0.5h, the temperature was raised to 45°C for cyclization reaction for 4h after the dropwise addition, acidified with hydrochloric acid to pH=0.5, cooled to 0°C and suction filtered to obtain a crude triazine ring. The crude product was dissolved in 52.5g of distilled water at 65°C, and the temperature was lowered. Crystallization at 10°C, suction filtration to obtain a triazine ring wet product, and drying at 90°C for 5 hours to obtain 14.66 g of a triazine ring dry product with a purity of 99.7% and a yield of 92.1%.

Embodiment 3

[0040] Add 10.5 g of 2-methylthiosemicarbazide, 15.6 g of diethyl oxalate, 24 g of methanol, and 36 g of ethanol to the reaction flask, drop to 10°C, and dropwise add a mixed alkali catalyst (30 g of sodium methoxide, 0.02 g of DMAP, 0.03 g of TMEDA) ) 1h, the temperature was raised to 50°C for 3h after the dropwise addition, and the hydrochloric acid was acidified to pH=0.7, cooled to 3°C and suction filtered to obtain a crude triazine ring. The crude product was dissolved in 60 g of distilled water at 68°C, cooled to 13°C for crystallization , suction filtration to obtain the triazine ring wet product, which is dried at 95° C. for 4 hours to obtain 14.72 g of the triazine ring dry product with a purity of 99.6% and a yield of 92.5%.

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Abstract

The invention belongs to the technical field of preparation of organic intermediates, and particularly relates to a preparation method of a triazine ring. The method comprises the following steps: adding 2-methyl thiosemicarbazide, diethyl oxalate and a mixed alcohol solvent into a reaction flask, dropwise adding a mixed base catalyst, carrying out cyclization reaction at 45-55 DEG C, performing acidifying with hydrochloric acid, performing cooling to 0-5 DEG C, and carrying out suction filtration to obtain a triazine ring crude product; dissolving the triazine ring crude product in distilled water at 65-70 DEG C, performing cooling to 10-15 DEG C, crystallizing to obtain a triazine ring wet product, and drying at 90-100 DEG C for 3-5 hours to obtain a triazine ring dry product. According to the preparation method, a new solvent system is not introduced, the reaction selectivity is high, side reactions are few, the solvent system is easy to recycle, and the product yield is high; the adopted raw materials are cheap, easy to obtain, low in cost and suitable for industrial amplification.

Description

technical field [0001] The invention belongs to the technical field of organic intermediate preparation, in particular to a preparation method of a triazine ring. Background technique [0002] Triazine ring (TTZ) is a key intermediate in the synthesis of ceftriaxone sodium, which has a wide range of applications in polymer materials, dyes, pesticides, and pharmaceutical industries, and has very important development value. [0003] Molecular formula: C 4 H 5 N 3 O 2 S. [0004] The structure is as follows: [0005] [0006] At present, the preparation method of triazine ring mainly contains the following 2 kinds: [0007] (1) take 2-methyl thiosemicarbazide and diethyl oxalate as raw materials, and sodium methoxide is a catalyzer to carry out cyclization reaction, this reaction needs a large amount of solvent system to complete, and this system is very viscous simultaneously, causing the local concentration to be inconsistent At the same time, the alkalinity of sod...

Claims

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Application Information

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IPC IPC(8): C07D253/07
CPCC07D253/07
Inventor 张林余成李剑
Owner SHANDONG JINCHENG KERUI CHEMICAL CO LTD
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