Novel application of the palladium-catalyzed N-arylation of hydrazones to a versatile new synthesis of pyrazoles

Fluorinated alcohols: A magic medium for the synthesis of heterocyclic compounds

“…Industrial and academic studies for the preparation of pyrazoles have led to numerous methodologies for the synthesis of these compounds [58][59][60][61][62][63][64][65][66][67]. A c c e p t e d M a n u s c r i p t …”

Infrared, Raman and NMR spectra, conformational stability, normal coordinate analysis and B3LYP calculations of 5-amino-4-cyano-3-(methylthio)-1H-pyrazole-1-carbothioamide

“…The vibrational assignment of pyrazole itself has been investigated; [11][12][13][14][15][16] however, there is little information regarding vibrational spectra and structure of substituted pyrazoles and N-substituted pyrazoles in particular [17,18]. The subject of the present study, 5-amino-4-cyano-3-(methylthio)-1H-pyrazole-1-carbothioamide, (AMPC, C 6 H 7 N 5 S 2 ) has several structural characteristics: it contains linear AC"N (sp), planar ANH 2 (sp 2 ) along with tetrahedral ACH 3 (sp 3 ) moieties in addition to the pyrazole ring. To the best of our knowledge, conformational stability, vibrational, 1 H, and 13 C NMR spectra, and barriers to internal rotation for AMPC have not been previously considered either experimentally or theoretically.…”

“…Pyrazoles are used extensively for the preparation of biologically active derivatives [1][2][3] with wide applications in the pharmaceutical industry [4][5][6][7][8] as analgesics, anti-inflammatory, antibacterial and antidepressant agents [9]. Recently amino-pyrazole derivatives were found to be potentially useful in preventing brain-protein aggregation which is the first phase in the development of Alzheimer's disease [10].…”

Five‐Membered Heterocycles: 1,2‐Azoles. Part 1. Pyrazoles

“…These hydrazones react with various 1,3-bifunctional substrates under acidic conditions to afford adequately functionalized pyrazoles in good yields (Scheme 8.37) [172,173]. The obtained regioselectivity is consistent with transhydrazonation followed by subsequent cyclization.…”