170569-87-6Relevant articles and documents
1,5-diarylpyrazole derivative, and synthetic method and application thereof
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Paragraph 0039; 0041; 0044-0046, (2021/07/01)
The invention relates to a 1,5-diaryl pyrazole derivative and antibacterial application thereof. On the basis of a celecoxib structure, structural modification is conducted on 1,5-diaryl to obtain the 1,5-diaryl pyrazole derivative; and after structural c
An Integrated Continuous Flow Micro-Total Ultrafast Process System (μ-TUFPS) for the Synthesis of Celecoxib and Other Cyclooxygenase Inhibitors
Sthalam, Vinay Kumar,Singh, Ajay K.,Pabbaraja, Srihari
, p. 1892 - 1899 (2019/10/11)
Integrated continuous manufacturing has emerged as a promising device for the rapid manufacturing of active pharmaceutical ingredients (APIs). We herein report a newly designed continuous flow micro-total process system platform for the rapid manufacturing of celecoxib, a selective nonsteroidal anti-inflammatory drug. This approach has been proven generally for the synthesis of several alkyl and aryl substituted pyrazoles. In order to minimize the tedious work-up process of potential reaction intermediates/products, we have developed a continuous flow extraction and separation platform to carry out the entire reaction sequence resulting in a short residence time with good yield. The present process was further extended to gram-scale synthesis of the COX-2-related API, viz. celecoxib, in the continuous flow process.
Selective, Metal-Free Approach to 3- or 5-CF3-Pyrazoles: Solvent Switchable Reaction of CF3-Ynones with Hydrazines
Muzalevskiy, Vasiliy M.,Rulev, Alexander Yu.,Romanov, Alexey R.,Kondrashov, Evgeniy V.,Ushakov, Igor A.,Chertkov, Vyacheslav A.,Nenajdenko, Valentine G.
, p. 7200 - 7214 (2017/07/26)
A detailed study of the reaction of trifluoroacetylated acetylenes and aryl (alkyl) hydrazines was performed, aimed to the regioselective synthesis of 3- or 5-trifluoromethylated pyrazoles. It was found that the regioselectivity of reaction depends dramatically on the solvent nature. Highly polar protic solvents (hexafluoroisopropanol) favor the formation of 3-trifluoromethylpyrazoles. In contrast, when the reaction was performed in polar aprotic solvents (DMSO), the formation of their 5-CF3-substituted isomers was preferentially observed. Alternatively, the regioselective assembly of 3-CF3-substituted pyrazoles can be performed via two-step one-pot procedure. The reaction of trifluoromethylated ynones with aryl (alkyl) hydrazines in the presence of acidic catalysts leads to formation of the corresponding hydrazones. The latter can be smoothly transformed into 3-CF3-pyrazoles by treatment with a base. This solvent-switchable procedure was used for the preparation of such important drugs as Celebrex and SC-560 as well as their isomers in gram scale. The possible reaction mechanism is discussed.
