Results 81 to 90 of about 1,937,826 (232)

Chemoselective synthesis of pyrazole derivatives via beta-enamino keto esters

, 2000
beta -Enamino keto ester (2a) reacts with hydroxylamine to give an isoxazole derivative (3). Compound (2a) reacts with hydrazine, alkyl- and arylhydrazines to give pyrazole derivatives (4a-e) as only reaction products.
C. F. Morelli, M. Manferdini, A. Veronese   +2 more
core   +1 more source

The Newly Synthesized Pyrazole Derivative 5-(1-(3 Fluorophenyl)-1H-Pyrazol-4-yl)-2H-Tetrazole Reduces Blood Pressure of Spontaneously Hypertensive Rats via NO/cGMO Pathway

Frontiers in Physiology, 2018
The search for new antihypertensive drugs has grown in recent years because of high rate of morbidity among hypertensive patients and several side effects that are associated with the first-line medications.
Neidiane R. Trindade, Paulo R. Lopes, Lara M. Naves, James O. Fajemiroye, Pedro H. Alves, Nathalia O. Amaral, Luciano M. Lião, Ana C. S. Rebelo, Carlos H. Castro, Valdir A. Braga, Ricardo Menegatti, Gustavo R. Pedrino   +11 more
doaj   +1 more source

Ullmann‐Type N‐Heteroarylation of Nitrogen Heterocycles Catalyzed by Heterogeneous CuNPs/HKUST‐1

EcoEnergy, EarlyView.
A practical strategy for the direct synthesis of CuNPs/HKUST‐1 heterogeneous catalyst was developed and used for the catalyzing Ullmann‐type N‐arylation of N‐heterocycles with high yields, excellent recyclability, and low copper leaching. ABSTRACT Ullmann‐type C–N coupling is an essential reaction to construct functional nitrogen heterocycles, whereas ...
Shuai Yang, Fangshu Han, Yamin Dong, Liangting Wu, Wenchao Tang, Changyan Guo, Jide Wang, Ablimit Abdukader, Chenjiang Liu, Yonghong Zhang   +9 more
wiley   +1 more source

Two tautomers in the same crystal: 3-(4-fluorophenyl)-1H-pyrazole and 5-(4-fluorophenyl)-1H-pyrazole

Acta Crystallographica Section E, 2014
The title co-crystal, 3-(4-fluorophenyl)-1H-pyrazole–5-(4-fluorophenyl)-1H-pyrazole (1/1), C9H7FN2, crystallizes with four independent molecules (A, B, C and D) in the asymmetric unit exhibiting two tautomeric forms (A and D; B and C) due to N—H proton ...
Thammarse S. Yamuna, Manpreet Kaur, Jerry P. Jasinski, Brian J. Anderson, H. S. Yathirajan   +4 more
doaj   +1 more source

The Serendipitous Discovery of Rollover Cyclometalation: From Unrecognized Observation to Transformative Chemistry

European Journal of Inorganic Chemistry, EarlyView.
Rollover cyclometalation is a distinctive variant of classical cyclometalation where a chelated heterocyclic ligand undergoes internal rotation, releasing one donor atom from coordination and subsequently activating a remote C─H bond with high regioselectivity.
Antonio Zucca, Maria I. Pilo
wiley   +1 more source

1H-pyrazole- azomethine based novel diazo derivative chemosensor for the detection of Ni2+

, 2020
In this study, 1H-pyrazole- azomethine based novel diazo derivative disperse azo dye was synthesized by a simple one-pot condensation reaction of 5-amino-3-methyl-4-phenylazo-1H-pyrazole (2) and salicylaldehyde in 1:1 ratio.
Demirçalı, Aykut, Söyleyici, Sevil, Karcı, Fikret, Erten, Gülnihal   +3 more
core   +1 more source

Enzymatic Transglycosylation Features in Synthesis of 8-Aza-7-Deazapurine Fleximer Nucleosides by Recombinant E. coli PNP: Synthesis and Structure Determination of Minor Products

Biomolecules
Enzymatic transglycosylation of the fleximer base 4-(4-aminopyridine-3-yl)-1H-pyrazole using recombinant E. coli purine nucleoside phosphorylase (PNP) resulted in the formation of “non-typical” minor products of the reaction.
Barbara Z. Eletskaya, Anton F. Mironov, Ilya V. Fateev, Maria Ya. Berzina, Konstantin V. Antonov, Olga S. Smirnova, Alexandra B. Zatsepina, Alexandra O. Arnautova, Yulia A. Abramchik, Alexander S. Paramonov, Alexey L. Kayushin, Anastasia L. Khandazhinskaya, Elena S. Matyugina, Sergey N. Kochetkov, Anatoly I. Miroshnikov, Igor A. Mikhailopulo, Roman S. Esipov, Irina D. Konstantinova   +17 more
doaj   +1 more source

Enantioselective Conjugate Addition of Malononitriles to Enynes: A Stereodivergent Approach to Chiral Allenes

European Journal of Organic Chemistry, EarlyView.
Quinine‐catalyzed enantioselective conjugate addition of malononitrile derivatives to enynes provides trisubstituted chiral allenes in good to excellent yields and high enantiopurities under mild conditions. Broad substrate scope, easy scalability, and versatile post‐synthetic transformations into enantioenriched pyrazoles and furans highlight the ...
Martin Kamlar, Josef Panenka, Ivana Císařová, Jan Veselý   +3 more
wiley   +1 more source

Mechanism of the Formation of 3-Nitro-5-(3'-pyridyl)- Pyrazole from Nicotine

, 1978
Natural Products Laboratory, School of Chemistry, University of Minnesota, Minneapolis, Minnesota, 55455, U.S.A. The yield of 3-nitro-5-(3'-pyridyl) pyrazole, obtained by the oxidation of nicotine with nitric acid, was increased by the addition of ...
EDWARD LEETE, HENRY V. ISAACSON
core   +1 more source

New Potent 5α- Reductase and Aromatase Inhibitors Derived from 1,2,3-Triazole Derivative

Molecules, 2020
This work describes the utility of pyrazole-4-carbaldehyde 1 as starting material for the synthesis of a novel potent series of 5α-reductase and aromatase inhibitors derived from 1,2,3-triazole derivative. Condensation of 1 with active methylene and
Mohamed El-Naggar, Amira S. Abd El-All, Shweekar I. A. El-Naem, Mohamed M. Abdalla, Huda R. M. Rashdan   +4 more
doaj   +1 more source