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Updated: Apr 15, 2026

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines
Published on: June 23, 2019
Synthesis toward CRHR1 Antagonists through 2,7-Dimethylpyrazolo[1,5-α][1,3,5]triazin-4(3H)-one C-H Arylation
Jinghai Long1, Woong-Sup Lee1, Chieyeon Chough1
1Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-747, Republic of Korea.
Abstract:
A novel synthetic protocol for 8-aryl substituted pyrazolo[1,5-α][1,3,5]triazin-4(3H)-ones was developed employing Pd-catalyzed C-H arylation. The reaction yield was influenced by the presence of a phosphine ligand, pivalic acid, and base selection. With the use of 5-10 mol % catalyst, reactions of 2 with p- or m-substituted aryl bromides proceeded in moderate to good yields. Lower yields were observed with o-substituted aryl bromides. Using this method a precursor for MJL1-109-2, a known nonpeptide CRHR-1 antagonist, was successfully synthesized.
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