On the basis of 102 assigned frequencies to in plane vibrations of pyrimidine, pyrimidine-2-d2, pyrimidine-2, 5-d2, pyrimidine-4,6-d2, pyrimidine-2,4,6-d3 and pyrimidine-d4, 35 valance force field constants including 14 principals and 21 interaction force constants are calculated. New assignments are suggested for n<su...

A series of tunable and regenerable biomimetic hydrogen sources, 4,5-dihydropyrrolo[1,2-a]quinoxalines, have been synthesized and applied in biomimetic asymmetric hydrogenation of 3-aryl-2H-benzo[b][1,4]oxazines and 1-alkyl-3-aryl-quinoxalin-2(1H)-ones, providing the chiral amines with up to 92% and 89% ee, respectively.

The syntheses of quinoxalines derived from 1,2-diamine and 1,2-dicarbonyl compounds under mild reaction conditions was carried out using a nanoparticle-supported cobalt catalyst. The supported nanocatalyst exhibited excellent activity and stability and it could be reused for at least ten times without any loss of activity. No cobalt contamination could be detected in the products by AAS measure...

there has been special interest in the chemistry of quinolone and pyrimidine derivatives due to their diverse biological activities such as anticonvulsant, anti-malarial agents, antibacterial, antiviral, cytostatic, antithelemintic, antigenotoxic, anti-cancer agents. these compounds are also used as targeting delayed-type hypersensivity and anti-convulsant agents. as a part of our research work...

The asymmetric organocatalytic hydrogenation of benzoxazines, quinolines, quinoxalines and 3H-indoles in continuous-flow microreactors has been developed. Reaction monitoring was achieved by using an inline ReactIR flow cell, which allows fast and convenient optimization of reaction parameters. The reductions proceeded well, and the desired products were isolated in high yields and with excelle...

A transition metal free tandem two-step strategy has been developed involving hydrolysis of 2-chloro-3-alkynyl quinoxalines/pyrazines followed by in situ cyclization of the corresponding 2-hydroxy-3-alkynyl intermediates in a single pot leading to fused furo N-heterocycles as potential inhibitors of sirtuins. A representative compound showed promising pharmacological properties in vitro and in ...

Novel syntheses of C-nucleoside analogs with aryl quinoxalines as nucleobase surrogates have been accomplished by mild and efficient three-component sequential reactions in high yields with a wide scope of substrates. The mechanism was clarified by isolation of novel sugar 1,2-diketone derived from oxidation of the corresponding alkyne.

Chlorination with equimolar POCl₃ can be efficiently achieved not only for hydroxypyrimidines, but also for many other substrates such as 2-hydroxy-pyridines, -quinoxalines, or even -amides. The procedure is solvent-free and involves heating in a sealed reactor at high temperatures using one equivalent of pyridine as base. It is suitable for large scale (multigram) batch preparations.

The synthesis of some 1,4-aryldiazines (novel and known dibenzo[a,c]phenazines and quinoxalines) based on the condensation of 1,2-aryldiamines with aromatic 1,2-dicarbonyl compounds in the presence of lithium chloride as a heterogeneous catalyst is presented as convenient and efficient strategy. This method has advantages such as excellent yields, short reaction times, and simple work-up proced...