Synthesis of novel 1,4,5-trisubstituted 3-trifluoromethylpyrazoles via microwave-assisted Stille coupling reactions

5-Methyl-N-[2-nitro-4-(trifluoromethyl)phenyl]-1H-pyrazole-3-amine: a chain of hydrogen-bondedR22(6) andR22(16) rings

“…In particular, aminopyrazoles containing functionalized substituents are very versatile intermediates for the synthesis of fused heterocyclic systems (Portilla et al, 2008;Quiroga et al, 2008). In addition, the introduction of a trifluoromethyl group into such compounds has often enhanced their biological activity (Jeon et al, 2007;Iaroshenko et al, 2009). As part of a synthetic study of such systems, compound (I) has been prepared in high yield by a nucleophilic aromatic substitution reaction between 5-amino-3-methyl-1H-pyrazole and 2-nitro-4-(trifluoromethyl)chlorobenzene.…”

4-(Pyrazol-4-yl)-pyrimidines as Selective Inhibitors of Cyclin-Dependent Kinase 4/6

“…The same Stille reaction conditions were applied to 9 to obtain 12 in 69% yield. 3-Trifluoromethylpyrazole 13 14 was protected with a N,N-dimethylsulfamoyl group and installed on the pyrimidine ring following the procedure developed by Strekowski et al 15 to give 14 (Scheme 4).…”

Synthesis, Crystal Structure, and Supramolecular Understanding of 1,3,5-Tris(1-phenyl-1H-pyrazol-5-yl)benzenes

“…Several synthetic methodologies have been employed in halogenation reactions of pyrazoles, including: CCl 4 , ethanol, water, DMF, acetonitrile, dichloromethane, THF, and ethyl acetate [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. The halogenation reactions of the 1,3,5- tris (1-phenyl-1 H -pyrazol-5-yl)benzenes 5 – 7 were performed with N -halosuccinimides 8a – c in ethanol reflux ( Scheme 2 ).…”