33641-15-5Relevant articles and documents
Preparation method of pyrazole type herbicide intermediate 1-methyl-5-hydroxypyrazole
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Paragraph 0035; 0038-0040; 0043-0045; 0048-0049, (2021/03/31)
The invention belongs to the technical field of preparation of pyrazole type herbicide intermediates, and particularly relates to a preparation method of a pyrazole type herbicide intermediate 1-methyl-5-hydroxypyrazole. The preparation method of the 1-methyl-5-hydroxypyrazole comprises the following steps: (1) in the presence of alkali, enabling dimethyl malonate of a compound (1) to react with aformamide compound and an alkylation reagent in a solvent to generate a compound (2); and (2) carrying out cyclization reaction on the obtained compound (2) and methylhydrazine/hydrazine hydrate in asolvent, and carrying out hydrolysis and decarboxylation by using an acid to obtain a compound (3). According to the method, DMF, an alkylation reagent and the compound (1) react to obtain the compound (2), the obtained compound (2) is good in selectivity when being subjected to ring-closure reaction with methylhydrazine (or hydrazine hydrate), and a target product compound (3) with higher yieldand purity can be obtained. Moreover, the raw materials used in the synthesis method disclosed by the invention are relatively weak in corrosivity, easy to recover and relatively low in price, so thatindustrial production is facilitated.
Method for preparing 1-methyl-5-hydroxypyrazole by using microchannel reactor
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Paragraph 0027-0048, (2021/06/22)
The invention relates to a method for preparing 1-methyl-5-hydroxypyrazole by using a microchannel reactor, and belongs to the technical field of fine chemical engineering. According to the invention, methyl 3-methoxyacrylate and a methylhydrazine aqueous solution are used as reaction raw materials, and the microchannel reactor is used as reaction equipment to prepare 1-methyl-5-hydroxypyrazole. Compared with a kettle type reaction, the yield and the reaction purity are obviously improved. In addition, no solvent is used in the preparation process, so that few hazardous wastes are generated. The microchannel reactor is used for preparing the 1-methyl-5-hydroxypyrazole, continuous production can be achieved, the operation process is simplified, and the production efficiency and safety are improved.
Pyrazole ketone compound or its salt, preparation method thereof, and use of the herbicide composition (by machine translation)
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Paragraph 0063; 006=5, (2016/10/08)
This application pertains to the field of agricultural chemicals, in particular to a pyrazole ketone compound or its salt, preparation method, herbicidal composition and use. The ketone compounds states the pyrazole shown as formula I: In the formula, R 1 R 2 N representative containing substituted or unsubstituted 1-3 of the aza-3-8-membered nitrogen-containing heterocyclic base; or R 1, R 2 respectively represents hydrogen, C 1-8 alkyl etc.; R 3 representative hydrogen, C 1-4 alkyl, alkenyl, alkynyl, or unsubstituted C 1-4 alkyl substituted C 3-6 cycloalkyl; R 4 represents methyl, ethyl, n-propyl, isopropyl, cyclopropyl; X represents hydrogen, -S (O) n R 6, -R 7, containing substituted or unsubstituted 1-4 of the aza-3-8-membered heterocyclic group, wherein n representative 1, 2, 3, R 6 represents a substituted or unsubstituted alkyl or aryl, R 7 represents a substituted or unsubstituted alkyl, aryl, alkanoyl or sweet-smelling acyl. The present invention provides good efficacy of the pharmaceutical actives, easy to use, low cost, has good commercial value. (by machine translation)