1192579-10-4Relevant academic research and scientific papers
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.
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
supporting information, 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
