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6-Azauracil
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Jan Slouka – One of the best experts on this subject based on the ideXlab platform.
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Synthesis of some symmetrically substituted compounds derived from 1,3-bis(6-Azauracil-1-yl)benzene and 1,3,5-tris(6-Azauracil-1-yl)benzene
Journal of Heterocyclic Chemistry, 2002Co-Authors: Petr Bilek, Jan SloukaAbstract:The 3,5-bis(5-carboxy-6-Azauracil-1-yl)aniline (7) and 1,3,5-tris(5-carboxy-6-Azauracil-1-yl)benzene (10) were prepared from 3-amino-5-nitroacetanilide (1) via intermediates 2–6. A series of other substituted 6-Azauracil derivatives 9, 11-14 were also prepared.
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1-ARYL-6-AzauracilS XLI # SYNTHESIS AND REACTIVITY OF 1-(3,5-DINITROPHENYL)-6-Azauracil-5-CARBONITRILE
, 2001Co-Authors: Facultas Rerum, Naturalium Chemica, Petr Bilek, Jan SloukaAbstract:Diazotization of 3,5-dinitroaniline either in acetic acid or nitrosylsulphuric acid afforded diazonium salt that after coupling either with ethyl cyanoacetylcarbamate or diethyl malonylbiscarbamate afforded corresponding hydrazones (2a) or (2b) respectively. After cyclization of (2a) in xylene we received 3,5-dinitrophenyl-6-Azauracil derivative (3a). This derivative underwent hydrolytic splitting of the triazine cycle by boiling in water pyridine solution resulting in 3,5-dinitrophenylhydrazonocyanoacetamide (4a) that was impossible to obtain directly by coupling reaction. Key words: Coupling reactions of 3,5-dinitrobenzenediazonium salts, splittin
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1-ARYL-6-AzauracilS XLI # SYNTHESIS AND REACTIVITY OF 1-(3,5-DINITROPHENYL) –6-Azauracil-5-CARBONITRILE
, 2001Co-Authors: Facultas Rerum Naturalium, Petr Bilek, Jan SloukaAbstract:Diazotization of 3,5-dinitroaniline either in acetic acid or nitrosylsulphuric acid afforded diazonium salt that after coupling either with ethyl cyanoacetylcarbamate or diethyl malonylbiscarbamate afforded corresponding hydrazones (2a) or (2b) respectively. After cyclization of (2a) in xylene we received 3,5-dinitrophenyl-6-Azauracil derivative (3a). This derivative underwent hydrolytic splitting of the triazine cycle by boiling in water pyridine solution resulting in 3,5-dinitrophenylhydrazonocyanoacetamide (4a) that was impossible to obtain directly by coupling reaction.
Jan Hlaváč – One of the best experts on this subject based on the ideXlab platform.
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SYNTHESIS OF 5-(M-TOLYL)-6-Azauracil AND SOME OF ITS DERIVATIVES
, 2000Co-Authors: Facultas Rerum, Naturalium Chemica, Jan Hlaváč, Jan Slouka, Pavel Hradil, Ar NAbstract:7-Methylisatin (I) was converted to appropriate semicarbazone (II). Its alkaline recyclization afforded 5-(2-amino-3-methyl)-6-Azauracil (III). Its diazotation and subsequent reductive elimination of diazonium group led to the 5-(m-tolyl)-6-Azauracil (VI). Appropriate hydrazone (V) was prepared by coupling of diazotated amine III with ethyl cyanoacetylcarbamate. After reaction with bicarbonate this compound was converted to 1-[2-(6-Azauracil-5-yl)-6-methylphenyl]-6-Azauracil-5-carbonitrile (VII). Cyclization of aminoderivative III afforded 3,5-dihydro-5H-6-methyl-[1,2,4]triazino[5,6-b]indole-3-one (VII) Key words: 5-aryl-6-Azauracils, twocyclic 6-Azauracils, [1,2,4]-triazino[5,6-b]indol
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cyclocondensation reactions of heterocyclic carbonyl compounds synthesis of 2 6 bis 6 azauracil 5 yl aniline and its use for synthesis of some other polynuclear 1 2 4 triazines
Journal of Heterocyclic Chemistry, 1997Co-Authors: Jan Hlaváč, Jan SloukaAbstract:5-(2-Aminophenyl)-6-Azauracil 1 was converted to 7-(6-Azauracil-5-yl)isatin 3, semicarbazone 4 of which was recyclized to 2,6-bis(6-Azauracil-5-yl)aniline 5. This one served as a starting compound for preparation of other noncondensed two nuclear heterocycles 7, 9, 10 and condensed 1,2,4-triazines 11 and 12 as well.
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Cyclocondensation reactions of heterocyclic carbonyl compounds.. Synthesis of 2,6‐bis(6‐azauracil‐5‐yl)aniline and its use for synthesis of some other polynuclear 1,2,4‐triazines
Journal of Heterocyclic Chemistry, 1997Co-Authors: Jan Hlaváč, Jan SloukaAbstract:5-(2-Aminophenyl)-6-Azauracil 1 was converted to 7-(6-Azauracil-5-yl)isatin 3, semicarbazone 4 of which was recyclized to 2,6-bis(6-Azauracil-5-yl)aniline 5. This one served as a starting compound for preparation of other noncondensed two nuclear heterocycles 7, 9, 10 and condensed 1,2,4-triazines 11 and 12 as well.
Xiaojun Liu – One of the best experts on this subject based on the ideXlab platform.
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Ultrafast Excited-State Dynamics of 6-Azauracil Studied by Femtosecond Transient Absorption Spectroscopy
The journal of physical chemistry. A, 2015Co-Authors: Xinzhong Hua, Linqiang Hua, Xiaojun LiuAbstract:The excited-state dynamics of 6-Azauracil in different solvents have been studied using femtosecond transient absorption spectroscopy. The molecule is populated to the S-2 state with a pump pulse at 264 nm. Broad-band white light continuum which covers from 320 to 600 nm is used as the probe. With a global fitting analysis of the measured transient spectra, three decay time constants, i.e., 1000 ps, are directly obtained in the solvent of acetonitrile. These newly observed lifetime constants are important in clarifying its decay dynamics as well as in providing a criterion for the ultrafast dynamics simulations in 6-Azauracil using quantum chemical theories. In combination with previous theoretical works, the main decay channel is proposed: the initially populated S-2 decays to S-1 through internal conversion in 1000 ps component is due to the decay of the T-1 state. A comparison of the excited-state dynamics in different solvents reveals that the decay from S, to T-1 shows a clear dependence on the polarity of the solvents. With higher polarity, the S-1 excited state decays faster. This observation is in line with the prediction by Etinski et al. [Phys. Chem. Chem. Phys. 2010, 12, 15665-15671], where a blue-shift of the T-1 state potential energy surface leading to an increase of the intersystem crossing rate was proposed. With the new information obtained in the present measurement, a clearer picture of the decay dynamics of 6-Azauracil on the S-2 excited state is provided.
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Ultrafast Excited-State Dynamics of 6‑Azauracil
Studied by Femtosecond Transient Absorption Spectroscopy, 2015Co-Authors: Xinzhong Hua, Linqiang Hua, Xiaojun LiuAbstract:The excited-state dynamics of 6-Azauracil
in different solvents
have been studied using femtosecond transient absorption spectroscopy.
The molecule is populated to the S2 state with a pump pulse
at 264 nm. Broad-band white light continuum which covers from 320
to 600 nm is used as the probe. With a global fitting analysis of
the measured transient spectra, three decay time constants, i.e.,
1000 ps, are directly obtained in
the
solvent of acetonitrile. These newly observed lifetime constants are
important in clarifying its decay dynamics as well as in providing
a criterion for the ultrafast dynamics simulations in 6-Azauracil
using quantum chemical theories. In combination with previous theoretical
works, the main decay channel is proposed: the initially populated
S2 decays to S1 through internal conversion
in 1000 ps component
is
due to the decay of the T1 state. A comparison of the excited-state
dynamics in different solvents reveals that the decay from S1 to T1 shows a clear dependence on the polarity of the
solvents. With higher polarity, the S1 excited state decays
faster. This observation is in line with the prediction by Etinski
et al. [Phys. Chem. Chem.
Phys. 2010, 12, 15665−15671], where a blue-shift of the
T1 state potential energy surface leading to an increase
of the intersystem crossing rate was proposed. With the new information
obtained in the present measurement, a clearer picture of the decay
dynamics of 6-Azauracil on the S2 excited state is provided