Results 171 to 180 of about 37,807 (249)

Reactivity of Cross-Conjugated Enynones in Cyclocondensations with Hydrazines: Synthesis of Pyrazoles and Pyrazolines.

Journal of Organic Chemistry, 2021
The cyclocondensation of cross-conjugated enynones, dienynones, and trienynones (easily available due to low-cost starting compounds) with arylhydrazines leads to the regioselective synthesis of pyrazole derivatives (dihetaryl-substituted ethens, buta-1 ...
A. Golovanov, I. Odin, D. Gusev, A. Vologzhanina, I. Sosnin, S. A. Grabovskiy   +5 more
semanticscholar   +1 more source

Synthesis of pyrazoles and condensed pyrazoles

Journal of Heterocyclic Chemistry, 1999
AbstractThis review introduces the synthesis of various pyrazoles reported by us and some other research groups during 1989–1998. Some of papers in this review deal with the development of potent pyrazoles or with the synthesis of potential pyrazoles aiming at agrochemicals and/or drugs.
Kenzi Makino, Ho Sik Kim, Yoshihisa Kurasawa   +2 more
openaire   +1 more source

Pyrazoles. III. PMR studies of pyrazoles

Recueil des Travaux Chimiques des Pays-Bas, 1967
AbstractSubstituents with electron withdrawing capacities are found to induce a paramagnetic displacement of the chemical shifts of protons and methyl groups in the remaining positions of the pyrazole ring. For the 4‐position this effect is considered to be due primarily to resonance interaction of substituent and pyrazole ring.
Clarisse L. Habraken, H. J. Munter, J. C. P. Westgeest   +2 more
openaire   +1 more source

Synthesis of Some Novel 2-{Pyrano[2,3-c]Pyrazoles-4-Ylidene}Malononitrile Fused with Pyrazole, Pyridine, Pyrimidine, Diazepine, Chromone, Pyrano[2,3-c]Pyrazole and Pyrano[2,3-d]Pyrimidine Systems as Anticancer Agents

Polycyclic aromatic compounds (Print), 2020
An unexpected efficient basic catalyzed heterocyclization reactions were carried out to build blocks of potentially bioactive 2-{pyrano[2,3-c]pyrazoles-4-ylidene}malononitrile skeleton fused with pyrazole, pyridine, pyrimidine, diazepine, chromone ...
D. Bakhotmah, T. Ali, M. Assiri, I. S. Yahia   +3 more
semanticscholar   +1 more source

Pyrazole–coumarin and pyrazole–quinoline chalcones as potential antitubercular agents

Archiv der Pharmazie, 2020
AbstractPyrazole, coumarin, and quinoline are medicinally important moieties. In this study, two series of novel pyrazole–coumarin chalcones and pyrazole–quinoline chalcones were synthesized using multiple‐step reactions. All the synthesized compounds were well characterized using different spectroscopic techniques including 1H and 13C nuclear magnetic
Gautam Kumar, Vagolu Siva Krishna, Dharmarajan Sriram, Sanjay M. Jachak   +3 more
openaire   +2 more sources

Antibacterial and antifungal pyrazoles based on different construction strategies.

European journal of medicinal chemistry
The growing prevalence of microbial infections, and antimicrobial resistance (AMR) stemming from the overuse and misuse of antibiotics, call for novel therapeutic agents, particularly ones targeting resistant microbial strains. Scientists are striving to
Muneeb Ur Rehman, Fang He, Xi Shu, Ju Guo, Ziwei Liu, Shuang Cao, Sihui Long   +6 more
semanticscholar   +1 more source

Transition Metal‐free C−H Sulfonylation and Pyrazole Annulation Cascade for the Synthesis of 4‐Sulfonyl Pyrazoles

, 2020
A practical protocol for the synthesis of 4‐sulfonyl pyrazoles via the reactions of readily available N,N‐dimethyl enaminones and sulfonyl hydrazines has been developed via the catalysis of molecular iodine in the presence of TBHP and NaHCO3 at room ...
Lihong Tian, Jie‐Ping Wan, Shou-Ri Sheng   +2 more
semanticscholar   +1 more source

ChemInform Abstract: Synthesis of Pyrazoles and Condensed Pyrazoles

ChemInform, 1999
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Kenzi Makino, Ho Sik Kim, Yoshihisa Kurasawa   +2 more
openaire   +1 more source

Nickel(II) complexes of pyrazole and substituted pyrazoles

Journal of Inorganic and Nuclear Chemistry, 1970
Abstract Complexes of pyrazole (pz), 3-methylpyrazole (3MePz) and 3,5-dimethylpyrazole (DMP) with nickel(II) salts can be crystallised from aqueous or ethanolic solutions. With pyrazole, tetragonal complexes of the type NiX2(pz)2 (X = Cl, Br) and Ni X 2 ( pz ) 4 (X = Cl, Br, NO 3 , 1 2 SO 4 ) are formed while 3-
D. Nicholls, B.A. Warburton
openaire   +1 more source

Pyrazole analogues of prazosin

Il Farmaco, 1998
A series of analogues of prazosin, in which 1-methyl or 1-phenylpyrazole moieties were substituted for the furan ring, were synthesized and studied for their alpha 1-adrenoceptor antagonist activity. The role of the five member heterocyclic substructures in determining the affinity for the alpha 1-receptor is briefly discussed.
G, Ermondi, D, Boschi, A, Di Stilo, C, Tironi, A, Gasco   +4 more
openaire   +2 more sources