Preparation method of amicarbazone

A technology of amfentrazone and amino, which is applied in the field of preparation of amfentrazone, can solve the problems of poor reaction selectivity, unsatisfactory reaction results, low boiling point of methyl acetate, etc., and achieves mild reaction conditions and strong reaction operability Effect

Pending Publication Date: 2021-12-28
北京怡力生物科技有限公司 +1
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Problems solved by technology

[0004] Unfortunately, the method provided by the above-mentioned patents has been tested many times, and the reaction results are not ideal, showing low reaction conversion rate and poor reaction selectivity
If other solvents such as acetone, tetrahydrofuran, ethylene glycol dimethyl ether, acetonitrile, etc. are used instead of methyl acet

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  • Preparation method of amicarbazone

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preparation example Construction

[0018] The invention provides a method for the preparation of amifentrazone, which comprises, under the catalysis of lithium hydroxide, 3-isopropyl-4-amino-1,2,4-triazolin-5-one (compound II ) and tert-butyl isocyanate (compound III) react chemically in acetonitrile to obtain the target product amenzazone. The reaction is characterized by high selectivity and high yield.

[0019] The applicant found that the lithium chloride in the composite catalyst reported in the patent US5708184 is almost insoluble in solvents such as methyl acetate, acetone, tetrahydrofuran, ethylene glycol dimethyl ether, and acetonitrile. Therefore, lithium chloride cannot effectively coordinate with the reaction substrate, resulting in poor reaction selectivity. Surprising discovery is, when using the lithium hydroxide of catalytic amount instead as catalyzer, when adopting acetonitrile as reaction medium simultaneously, compound (II) and compound (III) can take place chemical reaction smoothly, and t...

Embodiment 1

[0028] Under the protection of nitrogen flow, 360.00g of acetonitrile, 57.29g (0.575mol) of tert-butyl isocyanate, 0.71g (0.030mol) of powdered lithium hydroxide and 71.80g (0.500mol) of 3-isocyanate were successively put into the reaction flask. Propyl-4-amino-1,2,4-triazolin-5-one. Start stirring, heat up to 60° C., and keep the temperature for 60 minutes to complete the reaction. 6.00 g of acetic acid was added to neutralize the alkali in the reaction system, and samples were taken for high-performance liquid chromatography (HPLC) analysis. The reaction conversion rate was 97.9%, and the reaction selectivity was 98.2%.

[0029] After concentration and precipitation under negative pressure, 175ml of water was added, stirred, cooled to 10°C, and filtered. The filter cake was dried to obtain 116.19 g of amenzazone in the form of a white powdery solid with a purity of 97.6% and a yield of 94.0%.

Embodiment 2

[0031] Under the protection of nitrogen flow, 360.00g of acetonitrile, 0.71g (0.030mol) of powdered lithium hydroxide and 71.80g (0.500mol) of 3-isopropyl-4-amino-1,2,4- Triazolin-5-one. Start stirring, raise the temperature to 60° C., drop 57.29 g (0.575 mol) tert-butyl isocyanate into the reaction solution within 30 minutes, and then keep the temperature for 60 minutes. After the reaction was completed, 6.00 g of acetic acid was added to neutralize the alkali in the reaction system, and samples were taken for HPLC analysis. The reaction conversion rate was 97.8%, and the reaction selectivity was 98.7%.

[0032] After concentration and precipitation under negative pressure, 175ml of water was added, stirred, cooled to 10°C, and filtered. The filter cake was dried to obtain 116.78 g of amentrazone in the form of a white powdery solid with a purity of 97.7% and a yield of 94.6%.

[0033] The reactant and consumption of embodiment 1 and 2 are identical, and difference is only ...

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Abstract

The invention belongs to the field of organic synthesis, and discloses a preparation method of amicarbazone, and amicarbazone has a structure as shown in a formula (I) in the specification. The method comprises the following steps: carrying out chemical reaction on 3-isopropyl-4-amino-1, 2, 4-triazoline-5-ketone and tert-butyl isocyanate in an acetonitrile medium under the catalytic action of lithium hydroxide, and converting the 3-isopropyl-4-amino-1, 2, 4-triazoline-5-ketone and the tert-butyl isocyanate into the target product amicarbazone with high selectivity and high yield. The method has the advantages of mild reaction conditions, strong reaction operability and no strict requirements on the charging sequence, and is especially suitable for industrial mass production.

Description

technical field [0001] The invention belongs to the technical field of organic molecule synthesis, and in particular relates to a method for preparing amfentrazone. Background technique [0002] Amicarbazone is a triazolinone herbicide discovered by Bayer in 1988 and launched at the World Plant Protection Congress in Brighton, UK in 1999. Amfentrazone is a photosynthesis inhibitor, which is mainly absorbed through roots and leaves, and can effectively control various annual broad-leaved weeds and annual grass weeds that grow in corn fields, sugarcane fields, sugar beet fields, and lawns. The biggest advantage of amfentrazone is that it is safe for groundwater, safe for subsequent crops, and takes a long time for weeding. It is considered to be the best choice to replace the environmentally unfriendly herbicide atrazine. [0003] Bayer company reported a kind of synthetic method of amfentrazone in the patent US5708184, and this method uses the lithium chloride of catalytic a...

Claims

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Application Information

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IPC IPC(8): C07D249/12
CPCC07D249/12
Inventor 王文军吴少祥李静张金萍刘伟
Owner 北京怡力生物科技有限公司
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