5775-82-6Relevant articles and documents
Bromination of 1,3-dimethyl- and 1,5-dimethyl-1H-pyrazole-4-carboxylic acids [1]
Attaryan,Akopyan,Badalyan,Asratyan
, p. 307 - 308 (2007)
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Bromination of 1,3- and 1,5-dimethyl-1H-pyrazole-4-carbaldehydes
Attaryan,Akopyan,Badalyan,Minasyan,Asratyan
, p. 1740 - 1741 (2007)
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Preparation method of 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid ethyl ester
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Paragraph 0029-0032, (2020/06/20)
The invention discloses a preparation method of 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid ethyl ester, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: with 1,3-dimethylpyrazole as a raw material, carrying out halogenation to obtain 4-halogenated-1,3,5-tetrahydronaphthalene; carrying out a reaction under the conditions of a bromination reagent and AIBN and hydrolysis with hexamethylenetetramine to obtain 4-halogen-1-methyl-1H-pyrazole-3-formaldehyde, then performing a reaction with a fluorination reagent to obtain 4-halogen-3-difluoromethyl-1-methylpyrazole; finally carrying out a reaction on the 4-halogen-3-difluoromethyl-1-methylpyrazole and a Grignard reagent to obtain 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid ethyl ester. The method is simple and convenient to operate and high in reaction yield, the purity of the obtained product can reach 99.5% or above, and the method has a potential process amplification prospect.
PYRROLE COMPOUNDS, A PROCESS FOR THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM
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Paragraph 0330; 0331; 0332, (2015/02/19)
Compounds of formula (I): wherein A1, A2, Ra, Rb, Rc, Rd, R3, R4, R5 and T are as defined in the description. Medicinal products containing the same which are useful in treating pathologies involving a deficit in apoptosis, such as cancer, auto-immune diseases, and diseases of the immune system.