A novel, straightforward, and highly regioselective 4-chlorination of 3-oxypyrazole derivatives in boiling thionyl chloride (SOCl2) in the presence of catalytic N,N-dimethylformamide (DMF) has been developed. This reaction likely proceeds through a DMF-catalyzed electrophilic/nucleophilic chlorination mechanism and involves electrophilic attack by SOCl2 and nucleophilic substitution by Cl– as the key
Synthesis, biological evaluation, molecular modeling, and structural analysis of new pyrazole and pyrazolone derivatives as N‐formyl peptide receptors agonists
作者:Claudia Vergelli、Andrei I. Khlebnikov、Letizia Crocetti、Gabriella Guerrini、Niccolò Cantini、Liliya N. Kirpotina、Igor A. Schepetkin、Agostino Cilibrizzi、Mark T. Quinn、Patrizia Rossi、Paola Paoli、Maria Paola Giovannoni
DOI:10.1111/cbdd.13913
日期:2021.10
fragment, which was essential for activity. We report here new pyrazole and pyrazolone derivatives as restricted analogues of the above 6-membered compounds, all exhibiting the same 4-bromophenylacetamide side chain. Most new products had low or absent FPRagonist activity, suggesting that the pyrazole nucleus was not appropriate for FPRagonists. This hypothesis was confirmed by molecular modeling studies
Pd-catalyzed cross-coupling reactions of halogenated 1-phenylpyrazol-3-ols and related triflates
作者:Eglė Arbačiauskienė、Gytė Vilkauskaitė、Gernot A. Eller、Wolfgang Holzer、Algirdas Šačkus
DOI:10.1016/j.tet.2009.07.017
日期:2009.9
1-Phenyl-1H-pyrazol-3-ol was used as a versatilesynthon for the preparation of various 1-phenyl-1H-pyrazole derivatives substituted at C-3 and C-4 of the pyrazole nucleus and at the phenyl ring para-position. Treatment of 1-phenyl-1H-pyrazol-3-ol with triflic anhydride in the presence of base gave 3-trifloyloxy pyrazole, while bromination and iodination yielded the corresponding halogenated derivatives
An efficient synthetic route to construct ortho-substituted 1-phenyl-1H-pyrazole-4carboxaldehydes and the correspondingethanones starting from 1-phenyl-1H-pyrazol-3-ol is described. Carbon-carbon bond-forming Pd-catalysedcross-couplingreactions were applied for the functionalisation of the intermediate pyrazole triflates. Detailed NMR spectroscopic investigations were undertaken with all obtained