142623-90-3Relevant articles and documents
Synthesis of trifluoromethylated pyrazolidines by [3 + 2] cycloaddition
Peng, Xiansha,Huang, Danfeng,Wang, Ke-Hu,Wang, Yalin,Wang, Juanjuan,Su, Yingpeng,Hu, Yulai
, p. 6214 - 6222 (2017)
A highly efficient [3 + 2] cycloaddition between trifluoromethylated N-acylhydrazones and nitroolefins in the presence of potassium hydroxide under phase transfer catalysis is developed to afford potentially bioactive trifluoromethylated pyrazolidines, which can be further transformed into trifluoromethylated pyrazoles in good yields.
Cycloaddition of Trifluoroacetaldehyde N-Triftosylhydrazone (TFHZ-Tfs) with Alkynes for Synthesizing 3-Trifluoromethylpyrazoles
Wang, Hongwei,Ning, Yongquan,Sun, Yue,Sivaguru, Paramasivam,Bi, Xihe
supporting information, p. 2012 - 2016 (2020/03/04)
A transition-metal-free [3 + 2] cycloaddition between trifluoroacetaldehyde N-triftosylhydrazone (TFHZ-Tfs) and alkynes is reported. This protocol provides an operationally simple and general method for the synthesis of diverse 3-trifluoromethylpyrazoles in good to excellent yields with broad substrate scope, including aryl, heteroaryl, and alkyl terminal alkynes, and electron-deficient internal alkynes. The synthetic potential of this method was further demonstrated by the synthesis of an antiarthritic drug Celecoxib in multigram scale.
Regioselective Synthesis of 3-Trifluoromethylpyrazole by Coupling of Aldehydes, Sulfonyl Hydrazides, and 2-Bromo-3,3,3-trifluoropropene
Zhu, Chuanle,Zeng, Hao,Liu, Chi,Cai, Yingying,Fang, Xiaojie,Jiang, Huanfeng
supporting information, p. 809 - 813 (2020/02/04)
A general and practical strategy for 3-trifluoromethylpyrazole synthesis is reported that occurs by the three-component coupling of environmentally friendly and large-tonnage industrial feedstock 2-bromo-3,3,3-trifluoropropene (BTP), aldehydes, and sulfonyl hydrazides. This highly regioselective three-component reaction is metal-free, catalyst-free, and operationally simple and features mild conditions, a broad substrate scope, high yields, and valuable functional group tolerance. Remarkably, the reactions could be performed on a 100 mmol scale and smoothly afforded the key intermediates for the synthesis of celecoxib, mavacoxib, SC-560, and AS-136A. Preliminary mechanism studies indicated that a 1,3-hydrogen atom transfer process was involved in this transformation.
Trifluoromethyl substituted pyrazole derivative as 3- well as synthesis method and application thereof (by machine translation)
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Paragraph 0213-0223, (2019/12/31)
The invention belongs to, the technical field. of synthesis of medical materials, 3 - and particularly, 2 - relates to a method for mixing and reacting a compound with, an, 2 - organic solvent I through Colecoxib a, method of mixing reaction with an organ
A Unified Continuous Flow Assembly-Line Synthesis of Highly Substituted Pyrazoles and Pyrazolines
Britton, Joshua,Jamison, Timothy F.
supporting information, p. 8823 - 8827 (2017/07/17)
A rapid and modular continuous flow synthesis of highly functionalized fluorinated pyrazoles and pyrazolines has been developed. Flowing fluorinated amines through sequential reactor coils mediates diazoalkane formation and [3+2] cycloaddition to generate more than 30 azoles in a telescoped fashion. Pyrazole cores are then sequentially modified through additional reactor modules performing N-alkylation and arylation, deprotection, and amidation to install broad molecular diversity in short order. Continuous flow synthesis enables the safe handling of diazoalkanes at elevated temperatures, and the use of aryl alkyne dipolarphiles under catalyst-free conditions. This assembly-line synthesis provides a flexible approach for the synthesis of agrochemicals and pharmaceuticals, as demonstrated by a four-step, telescoped synthesis of measles therapeutic, AS-136A, in a total residence time of 31.7 min (1.76 g h?1).
Highly tunable fluorinated trispyrazolylborates [HB(3-CF3-5-{4-RPh}pz)3]- (R = NO2, CF3, Cl, F, H, OMe and NMe2) and their copper(i) complexes
Van Dijkman, Thomas F.,Siegler, Maxime A.,Bouwman, Elisabeth
, p. 21109 - 21123 (2015/12/11)
The ethene and carbon monoxide adducts of copper(i) with seven trispyrazolylborate ligands ([HB(3-CF3-5-{4-RPh}pz)3]-; R = NO2 (4a), CF3 (4b), Cl (4c), F (4d), H (4e), OMe (4f) and NMe2 (4g)) were synthesized and characterized. The ligands were synthesized from their corresponding pyrazoles and sodium tetrahydridoborate and were obtained as solvent adducts of their sodium salts after workup. When the pyrazole with the most electron-withdrawing substituent (R = NO2) is used the asymmetric ligand [HB(3-CF3-5-{4-NO2Ph}pz)2(3-{4-NO2Ph}-5-CF3pz)]- (4a′) is formed as the major product. Copper(i) complexes with ethene or CO as a co-ligand were prepared in good yields and were structurally characterized using 1H NMR, 13C NMR and infrared spectroscopy. Single crystal X-ray crystallography analyses revealed the structures of Na4a′, Na4b, four copper ethene complexes and four copper carbonyl complexes. The structures of the copper(i) complexes show CuI ions in pseudo-tetrahedral coordination environments consisting of three nitrogen atoms of the trispyrazolylborate ligand and the carbonyl or η2-coordinated ethene ligands, with nearly identical coordination environments around the CuI ion. The compound [Na(4a′)(H2O)]n crystallizes as one-dimensional chains with intermolecular Na...O2N interactions. The sodium ions were found in severely distorted octahedral geometries with three nitrogen atoms from the trispyrazolylborate ligand, one aqua ligand and two oxygen atoms from the nitro group of an adjacent molecule. The compound [Na2(4b)2(μ-H2O)2] crystallizes as a centrosymmetric water-bridged dimer: two five-coordinate square-pyramidal sodium ions each are coordinated facially by three nitrogen atoms from a trispyrazolylborate ligand and two bridging water ligands. Below the base of the pyramidal structure one intermolecular and two intramolecular Na...F short contacts are present. The 1H and 13C NMR spectra of the copper-ethene complexes show signals for the ethene ligands in the range of 4.84-4.96 ppm and 84.9-86.8 ppm respectively. The infrared spectra of the carbonyl complexes show CO stretching frequencies in the range of 2096-2120 cm-1. Both the NMR signals for the ethene ligands and infrared signals for the carbonyl ligands were found to show good correlations with the Hammett σp parameters of the substituents on the phenyl rings of the ligands.
An efficient route to 3-trifluoromethylpyrazole via cyclization/1,5-H shift and its applications in the synthesis of bioactive compounds
Wang, Yongdong,Han, Jing,Chen, Jie,Cao, Weiguo
, p. 8256 - 8262 (2015/10/05)
A methodology for regioselective synthesis of 3-trifluoromethylpyrazole from the reaction of trifluoromethyl alkenone and tosylhydrazone has been developed. The reaction was proposed to proceed through a tandem cyclization and 1,5-H shift reaction, which can be applied to the synthesis of bioactive compounds like Celecoxib, Mavacoxib, and SC-560.
Silver-mediated cycloaddition of alkynes with CF3CHN 2: Highly regioselective synthesis of 3-trifluoromethylpyrazoles
Li, Feng,Nie, Jing,Sun, Long,Zheng, Yan,Ma, Jun-An
, p. 6255 - 6258 (2013/07/05)
Silver screen: The title reaction provides a convenient and efficient method for the construction of 5-substituted 3-trifluoromethylpyrazoles under mild reaction conditions. By using this protocol, the marketed drug Celecoxib (antiarthritic) could be easily synthesized (see scheme; DMF=N,N- dimethylformamide). Copyright
Some novel observations on the reaction of 2-hydrazino-3-methylquinoxaline with trifluoromethyl-β-diketones
Aggarwal, Ranjana,Kumar, Rajiv,Singh, Shiv P.
experimental part, p. 886 - 893 (2009/12/30)
The reaction of 2-hydrazino-3-methylquinoxaline 1 with trifluoromethyl-β-diketones 2 not only yields the expected 5-trifluoromethyl-5-hydroxy-Δ2-pyrazolines 3a-3f and/or 3-trifluoromethylpyrazoles 4c-4f but also the unexpected products 1,2,4-tr
