- Regioselective synthesis of 1,2,4-triazin-5-one via gas-phase pyrolysis of 4-arylidenimino-3(2H)-thioxo-1,2,4-triazin-5(4H)-one. Kinetic and mechanistic study
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4-Arylidenimino-3(2H)-thioxo-1,2,4-triazin-5(4H)-ones (1a-e) and 4-arylidenimino-3-methylthio-1,2,4-triazin-5(4H)-ones (2a-e) were synthesized. Pyrolytic deprotection of these substrates were carried out. The kinetic results, product analysis and theoretical studies lend support to a reaction pathway involving a six-membered transition state in which the carbonyl and not thione bond attacks the hydrogen atom of the arylidenimino group. This reaction represents an efficient, clean and general synthetic procedure for the protection and selective synthesis of potential biologically active triazines and their derivatives. Copyright
- Al-Etaibi, Alya,Abdallah, Mariam,Al-Awadi, Nouria,Ibrahim, Yehia,Hasan, Mohammad
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- 3,5-dioxo-(2H,4H)-1,2,4-triazine derivatives as 5HT1A ligands
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A 3,5-dioxo-(2H,4H)-1,2,4-triazine compounds of formula I STR1 in which: R1 and R2, which are identical or different, represent hydrogen or C1 -C6 alkyl, n is 2 to 6, inclusive, A represents aryl piperazino II STR2 the Ar grouping representing phenyl, naphthyl, pyrimidyl, or pyridyl, unsubstituted or substituted by C1 -C3 alkyl, C1 -C3 alkoxy, hydroxy, trifluoromethyl, or halogen, or III benzodioxanyl-methyl-amino or pyridodioxanyl-methyl-amino STR3 in which R represents hydrogen or C1 -C3 alkyl and X represents a nitrogen or carbon atom, therapeutically-acceptable salts and enantiomers thereof, pharmaceutical compositions thereof, and method for treatment of diseases requiring a 5HT1A receptor agonist therewith.
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- Infrared spectra of 6-azathiouracils: An experimental matrix isolation and theoretical ab initio SCF/6-311G study
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The infrared (IR) absorption spectra of 2-thio-6-azauracil, 4-thio-6-azauracil and 2,4-dithio-6-azauracil isolated in low-temperature Ar and N2 matrices are reported. These compounds have been found to exist in low-temperature matrices exclusively in the oxothione and dithione tautomeric forms. An assignment of the observed infrared bands is proposed on the basis of comparison of the experimental matrix spectra with the spectra calculated at the ab initio SCF/6-311G** level. The IR spectra of the title compounds are compared with the previously published IR spectra of matrix isolated 2-thiouracil, 4-thiouracil and 2,4-dithiouracil.
- Lapinski, Leszek,Prusinowska, Dorota,Nowak, Maciej J.,Bretner, Maria,Felczak, Krzysztof,Maes, Guido,Adamowicz, Ludwik
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p. 645 - 659
(2007/10/03)
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- Chemotherapeutic agents: Part XXVI - Synthesis and evaluation of π-deficient symmetrical and unsymmetrical triazines as antimalarials
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1,2,4-Triazine derivatives (3-6) have been prepared by the electrophilic substitution on 2.Symmetrical triazines 8 and 11 have been obtained by nucleophilic reaction of dicyandiamide with nitriles 7 and 9.
- Ram, Vishnu J.,Nath, Mahendra
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p. 423 - 426
(2007/10/03)
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- Photochemical Cyclization of Some Aldehyde Thiosemicarbazones
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The photochemical behaviour of some substituted aldehyde thiosemicarbazones 1a-k has been investigated in methanol at 254 nm.Thiosemicarbazones of glyoxil methyl ester 1a-f cyclized to furnish the 3-thioxo-1,2,4-triazin-5-one 2-ring system.The remaining thiosemicarbazones 1g-j gave 1,2,4-triazoline 4-derivatives.
- Gruttadauria, Michelangelo,Buccheri, Francesco,Buscemi, Silvestre,Cusmano, Giuseppe,Noto, Renato,Werber, Giuseppe
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p. 233 - 236
(2007/10/02)
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- PALLADIUM-CATALYZED CYCLIZATION REACTIONS. UNICQUE SYNTHESIS OF CONDENSED THIAZOLES
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The facile synthesis of 3-methylene-2,3-dihydro-5H-thiazolopyrimidin-5-ones (9) has been performed by the catalytic action of a Pd(II) salt on 4-propargylthiopyrimidin-2(1H)-ones (6).Similar Pd(II)-catalyzed cyclization of 3-propargylthio-1,2,4-triazin-5(2H)-ones (10) gives 6-methylene-6,7-dihydro-4H-thiazolotriazin-4-ones (11) as a main product. 3-methylene-2,3-dihydro-7H-thiazolotriazin-7-ones (12), the regioisomers of 11, are provided by a base-catalyzed cyclization of 10.
- Mizutani, Masato,Sanemitsu, Yuzuru,Tamaru, Yoshinao,Yoshida, Zen-Ichi
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p. 305 - 314
(2007/10/02)
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- PALLADIUM-CATALYZED CYCLIZATION REACTIONS OF 3-PROPARGYLTHIO-1,2,4-TRIAZIN-5(2H)-ONES TO THIAZOLO-1,2,4-TRIAZINONES
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Selective transformation of 3-propargylthio-1,2,4-triazin-5(2H)-ones (1) to 6-methylene-6,7-dihydro-4H-thiazolo- triazin-4-ones (2) and 3-methylene-2,3-dihydro-7H-thiazolotriazin-7-ones (3) is performed under the conditions of Pd(II) salt or sodium hydroxide catalysis, respectively.
- Mizutani, Masato,Sanemitsu, Yuzuru,Tamaru, Yoshinao,Yoshida, Zen-ichi
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p. 1237 - 1240
(2007/10/02)
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