Results 31 to 40 of about 37,751 (208)

Ring Cleavage of Some Bicylic Compounds Derived from 1,2,4-Triazine [PDF]

Iranian Journal of Chemistry & Chemical Engineering, 1995
Ring cleavage occurred when 1,2,4-triazino-1,2,4-triazines (3), (4) and (5) were treated with concentrated hydrochloric acid to yield N-substituted triazines (7) and (8). These confirm the given configuration assigned to the isomeric triazinotriazines. 6-
Majid M. Heravi, Mehdi Bakavoli, Zohreh Sadjadi Hashemi   +2 more
doaj  

Synthesis and Photophysical Properties of α-(N-Biphenyl)-Substituted 2,2′-Bipyridine-Based Push–Pull Fluorophores

Molecules, 2022
A series of new α-(N-biphenyl)-substituted 2,2′-bipyridines were obtained through the combination of the ipso-nucleophilic aromatic substitution of the C5-cyano group, aza-Diels–Alder and Suzuki cross-coupling reactions, starting from 5-cyano-1,2,4 ...
Ekaterina S. Starnovskaya, Dmitry S. Kopchuk, Albert F. Khasanov, Olga S. Taniya, Igor L. Nikonov, Maria I. Valieva, Dmitry E. Pavlyuk, Alexander S. Novikov, Grigory V. Zyryanov, Oleg N. Chupakhin   +9 more
doaj   +1 more source

Dearomative [4 + 2] Annulation of Electron-Poor N‑Heteroarenes with Azoalkenes for Access to Polycyclic Tetrahydro-1,2,4-triazines

, 2023
A direct dearomative [4 + 2] annulation of electron-poor N-heteroarenes with azoalkenes generated in situ from α-halogeno hydrazones was developed under mild conditions.
Yu-Qing Guan, Dong-Chao Wang (1863811), Hai-Ming Guo (1395550), Jia-Hui Liu (1841488), Jia-Hui Liu, Yu-Qing Guan (5810885), Dong-Chao Wang, Hai-Ming Guo   +7 more
core   +1 more source

A Regioselective Approach to 5-Substituted-3-amino-1,2,4-triazines

, 2016
Nucleophilic displacement of readily available α,α-dibromoketones with excess morpholine gave the corresponding ketoaminals, which upon condensation with aminoguanidine in MeOH in the presence of AcOH afforded 5-substituted-3-amino-1,2,4-triazines in >95%
Paul N. Devine (1831207), Robert A. Reamer (1433476), John Limanto (1433470), Richard A. Desmond (2454514), Donald R. Gauthier (1633033), R. P. Volante (2664142)   +5 more
core   +1 more source

Arylation of 1,2,4-triazines in the presence of AlCl3 [PDF]

, 2014
This paper presents a method for introducing toluene and bromobenzene moieties into 1,2,4-triazines as an alternative to cross-coupling reactions. It is demonstrated that the C=N bond of a wide range of 1,2,4-triazines undergoes addition of arenes in the
Egorov, I. N.
core   +1 more source

Synthesis of 1,2,4-triazines and the triazinoisoquinolinedione DEF ring system of noelaquinone. [PDF]

Org Biomol Chem, 2012
The intramolecular Staudinger-aza-Wittig reaction is used for a general synthesis of 1,2,5,6-tetrahydro-1,2,4-triazines, a structural motif reported for the natural product noelaquinone.
Cao L, Maciejewski JP, Elzner S, Amantini D, Wipf P.   +4 more
europepmc   +2 more sources

A Direct Route to 6,6’-Disubstituted-2,2’-Bipyridines by Double Diels-Alder/retro Diels-Alder Reaction of 5,5’-bi-1,2,4-Triazines

Molecules, 2005
Inverse electron demand Diels-Alder reaction of functionalized 5,5’-bi-1,2,4- triazines with bicyclo[2.2.1]hepta-2,5-diene in boiling p-cymene leads to a range of 6,6’- disubstituted-2,2’-bipyridines in good yield.
D. Branowska
doaj   +1 more source

One-Pot Acid-Catalyzed Ring-Opening/Cyclization/Oxidation of Aziridines with N-Tosylhydrazones: Access to 1,2,4-Triazines [PDF]

, 2017
A new, three-step, telescoped reaction sequence for the regioselective conversion of N-tosyl hydrazones and aziridines to 3,6-disubstituted and 3,5,6-trisubstituted 1,2,4-triazines is described. The process involves an efficient nucleophilic ring opening
Lorène Crespin, Lorenzo Biancalana (2572165), David C. Blakemore, Crespin L., Tobias Morack, Ley S. V., Morack T., Biancalana L., Lorène Crespin (3748822), David C. Blakemore (465247), Steven V. Ley, Tobias Morack (3748825), Blakemore D. C., Lorenzo Biancalana, Steven V. Ley (532034)   +14 more
core   +2 more sources

Microwave Assisted Synthesis of Some New Fused 1,2,4-Triazines Bearing Thiophene Moieties With Expected Pharmacological Activity

Molecules, 2011
Rapid and efficient solvent-free synthesis of 4-amino-3-mercapto-6-[2-(2-thienyl)vinyl]-1,2,4-triazin-5(4H)-one 1 under microwave irradiation is described. Some new fused heterobicyclic nitrogen systems such as 1,2,4-triazino[3,4-b][1,3,4]thiadiazinones,
Mosselhi A. Mosselhi, Mohamed M. Youssef, Hosam A. Saad   +2 more
doaj   +1 more source

Structure–Activity Relationships in Methyl‐Driven Overhauser Effect DNP

Chemistry – A European Journal, EarlyView.
Dynamic nuclear polarization (DNP) was investigated in a wide array of methyl‐containing Blatter radicals to identify design principles for the synthesis of an Overhauser DNP polarizing agent. Fourteen different radicals were synthesized, which revealed that only radicals possessing sterically unhindered methyl groups in sites of high spin density were
Ananya Mukherji, Emma A. Foley, Shubha S. Gunaga, Thierry Dubroca, Mukaila A. Ibrahim, Jin‐Seok Yi, Nisreen Sharara, Syed Raza, Fadwat Bazzi, Simona Marincean, Dragos F. Flesariu, Panayiotis A. Koutentis, Frédéric Mentink‐Vigier, Takeshi Kobayashi, Christos P. Constantinides, Frédéric A. Perras   +15 more
wiley   +1 more source