- Palladium and Copper Cocatalyzed Intermolecular Cyclization Reaction: Synthesis of 5-Aminopyrazole Derivatives
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A novel and efficient palladium and copper co-catalyzed intermolecular cyclization of acetonitriles with hydrazones has been developed for the synthesis of 5-aminopyrazoles through C-C and C-N bond formation. The reaction has the advantages of easily avai
- Ma, Chaowei,Wen, Ping,Li, Jihui,Han, Xu,Wu, Zhaoyang,Huang, Guosheng
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p. 1073 - 1077
(2016/04/09)
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- New synthesis and reactions of ethyl 5-amino-4-cyano-1-phenyl-1H-pyrazole- 3-carboxylate
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Synthesis of ethyl 5-amino-4-cyano-1-phenyl-1H-pyrazole-3-carboxylate 5 has been achieved via abnormal Beckmann rearrangement of o-chloroaldehyde 1. Reaction of o-aminocarbonitrile 5 with concentrated H2SO4 furnished expected o-amino
- Gangurde, Sachin A.,Kanawade, Shrikant B.,Nikam, Prashant S.,Bhavsar, Dinesh C.,Toche, Raghunath B.
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p. 883 - 890
(2014/08/05)
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- Synthesis, cannabinoid receptor affinity, and molecular modeling studies of substituted 1-aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3-carboxamides
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The new 1-phenyl-5-(1H-pyrrol-1-yl)pyrazole-3-carboxamides were compared with the reference compounds AM251 and SR144528 for cannabinoid hCB1 and hCB2 receptor affinity. Compounds bearing 2,4-dichlorophenyl or 2,4-difluorophenyl groups at position 1 and 2,5-dimethylpyrrole moiety at position 5 of the pyrazole nucleus were generally more selective for hCB 1. On the other hand, the N-cyclohexyl group at the 3-carboxamide was the determinant for the hCB2 selectivity, in particular when a 3,4-dichlorophenyl group was also present at position 1. Compound 26 was the most selective ligand for the hCB1 receptor (Ki (CB 2)/Ki (CB1) = 140.7). Derivative 30, the most potent hCB1 ligand (Ki = 5.6 nM), was equipotent to AM251 and behaved as an inverse agonist in the cAMP assay (EC50 ~1 nM). The carbonyl oxygen of both 26 and 30 formed a H-bond with K3.28(192), while the substituents at the nitrogen fitted in a pocket formed by lipophilic residues. This H-bonding interaction was proposed to account for the high affinity for receptors' inactive state and the inverse agonist activity.
- Silvestri, Romano,Cascio, Maria Grazia,La Regina, Giuseppe,Piscitelli, Francesco,Lavecchia, Antonio,Brizzi, Antonella,Pasquini, Serena,Botta, Maurizio,Novellino, Ettore,Di Marzo, Vincenzo,Corelli, Federico
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p. 1560 - 1576
(2008/12/20)
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- Heterocyclic Synthesis Using Hydrazonoyl Halides: Synthesis of Annelated Pyrimidines, Pyridazines and Pyrazoles
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Aminocyanopyrazoles and dihydropyrrolopyrazole-4,6-diones were obtained in good yields by the reaction of hydrazonoyl halides with malononitrile and N-arylmaleimides respectively. Pyrazolopyrimidines and pyrazolopyridazines were synthesized in quantitative yields by the reaction of formic acid or formamide and hydrazine hydrate with aminocyanopyrazoles. Novel ring systems, 4-mercapto-1,2,3,5,6,7-hexaazaacenaphthylenes 20 and 7-thia-1,2,4,5,6,10-hexaazacyclopentacenaphthylenes 22 were prepared by the reaction of 18 with carbon disulfide and the reaction of 21 with acetic anhydride. The structures of the products were assigned and confirmed on the basis of their elemental analyses, spectral data and alternate synthesis wherever possible.
- Abdelhamid, Abdou O.
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p. 1239 - 1262
(2007/10/02)
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