- Preparation method of metamitron
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The invention belongs to the technical field of organic matter preparation, and particularly discloses a preparation method of metamitron. The preparation method comprises the following steps: carrying out heat preservation on ethyl benzoylformate, hydrochloric acid and an acethydrazide solution at 25-28 DEG C for 2.5-3 hours, cooling, crystallizing, filtering and washing to obtain 2-acethydrazide ethyl benzoylformate; then mixing with methanol to prepare a mixed solution, adding hydrazine hydrate at 16-20 DEG C, and reacting to obtain 2-acethydrazide hydrazone-2-phenyl-acethydrazide; then adding methanol and sodium acetate, heating and refluxing at 90-94 DEG C for 8-9 hours, and cooling for 1.8-2.2 hours to obtain metamitron. According to the method, the preparation temperature and the preparation time of the 2-acethydrazide benzoyl ethyl formate are reduced, and the yield of metamitron is increased.
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- Method for preparing metribuzin by one-pot method
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The invention discloses a method for preparing metribuzin by a one-pot method. The method comprises the following steps: (1) carrying out a first-step reaction on ethyl benzoylformate and acethydrazide in the presence of an alcohol solvent and ethylenediamine tetraacetic acid; (2) carrying out a second-step reaction on the reaction solution in the step (1) and hydrazine hydrate; (3) carrying out athird-step reaction on the reaction solution in the step (2) in the presence of a water absorbent and a phase transfer catalyst; and (4) carrying out post-treatment on the reaction solution obtainedin the step (3) to obtain metamitron. According to the method, the high-yield one-pot method for preparing the metamitron is finally realized by selecting proper material ratio and reaction temperature, particularly selecting an acid catalyst in the first-step reaction, the total yield can reach 90% or above, and the method is simple and convenient to operate, low in production cost and suitable for industrial mass production.
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Paragraph 0032-0042
(2020/07/21)
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- Production method of metamitron
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The invention discloses a production method of metamitron. The production method is characterized by comprising the following steps that benzoyl cyanide is hydrolyzed under the condition of H2SO4, and is then alcoholized into ester; hydrazine hydrate and methyl acetate take reaction to generate acetyl hydrazine hydrate; methyl benzoylformate and the acetyl hydrazine hydrate take reaction to generate hydrazine hydrate ester under the condition of H2SO4; hydrazine hydrate ester suspension and hydrazine hydrate take reaction; acyl is subjected to hydrazine treatment again to generate benzoyl hydrazine, and byproducts of methyl alcohol and water are generated; the benzoyl hydrazine is subjected to distillation, backflow, dehydration, cyclization and crystallization under the condition with a butanol solvent and a catalyst to generate the metamitron. The production method has the advantages that the cost of phase transfer catalysts is low; the cost of sodium benzoate is lower than that of sodium acetate, so that the production cost is reduced.
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- USE OF GLYCEROL ETHERS AS ACTIVATORS OF THE BIOLOGICAL EFFECTS OF A HERBICIDE, FUNGICIDE OR INSECTICIDE SUBSTANCE
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The invention relates to the use of glycerol ethers as agents that activate the biological effects of at least one substance selected from a herbicide, fungicide or insecticide. The invention essentially relates to the use of glycerol ether as an agent that activates the biological effects of at least one substance selected from a herbicide, or fungicide or insecticide, said glycerol ether having formula (1), wherein R1 represents an alkyl group having between 1 and 18 carbon atoms and R2 represents a hydrogen atom or an alkyl group having between 1 and 18 carbon atoms, preferably a methyl or ethyl group. The invention also relates to a phytosanitary composition containing one such glycerol ether, as well as to a phytosanitary treatment method using said composition.
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- Hydrazidines, IV. - Reaction of Hydrazidines with 1,2-Bifunctional Compounds
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Hydrazide hydrazones 1 react with 1,2-bifunctional compounds (2, 21, 23, 26, 30, 32) to give preferentially 4-amino-1,2,4-triazines (9, 13, 22, 25, 27, 31, 35).Some reactions of these substances are described.
- Neunhoeffer, Hans,Koehler, Gernot,Degen, Hans-Juergen
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- Preparation of 3,6-disubstituted 4-amino-1,2,4-triazin-5-ones
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The herbicidal 3,6-substituted 4-amino-1,2,4-triazin-5-one of the general formula STR1 wherein R1 and R2 have the meaning given in the description, is obtained in good yields by a new two-stage cyclization reaction if an α-ketocarboxylic acid amide of the general formula is reacted with a hydrazidine of the general formula STR2 if appropriate in the presence of a diluent at temperatures between 0° and 150° C., whereby in the first process stage a condensation reaction takes place to give condensation products which still have open chains, and in the second process stage an elimination reaction with ring closure takes place to give the end product of formula (I).
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- 5,6-Dihydro-1,2,4,6-thiatriazin-5-one-1,1-dioxides
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5,6-Dihydro-1,2,4,6-thiatriazin-5-one-1,1-dioxides of the formula STR1 where R1 is hydrogen, a metal atom or an unsubstituted or substituted ammonium radical, R2 is a saturated or unsaturated straight-chain aliphatic radical of up to 10 carbon atoms, a cycloaliphatic radical or 3 to 7 carbon atoms, a branched saturated or unsaturated aliphatic radical of 3 to 10 carbon atoms, a halogen-, alkoxy- or alkylmercapto-substituted aliphatic radical of 2 to 10 carbon atoms tetrahydrofuryl substituted methyl, a cycloalkoxy-substituted aliphatic radical of 4 to 10 carbon atoms, unsubstituted or halogen-substituted benzyl or phenyl, halophenyl, or alkylphenyl of a total of up to 10 carbon atoms, R3 is hydrogen, a straight-chain aliphatic radical of up to 10 carbon atoms, a cycloaliphatic radical of 3 to 7 carbon atoms, a branched aliphatic radical of 3 to 10 carbon atoms, haloalkyl, or alkoxyalkyl of 2 to 10 carbon atoms and X is oxygen and may also be sulfur if R2 is unsubstituted or halogen-substituted benzyl, processes for their preparation, and herbicides containing the above compounds.
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- Process for the preparation of certain acyl cyanide compounds
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Acyl cyanide compounds of the formula STR1 are prepared by reacting an acid halide of the formula STR2 with anhydrous hydrocyanic acid in the presence of a tertiary amine at a temperature between -70° and +100° C. R can be hydrocarbyl or substituted hydrocarbyl and X is halogen.
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- Glyoxylic acid hydrazide-2-acylhydrazone compounds
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Novel glyoxylic acid hydrazide-2-acylhydrazones of the formula: EQU1 in which R1 is hydrogen or alkyl, and R2 is alkyl or optionally substituted phenyl and are prepared by reacting the corresponding glyoxylic acid ester 2-acylhydrazone with hydrazine hydrate. The compounds (I) are useful in preparing herbicidally active 4-amino-1,2,4-triazin-5-one compounds.
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