- Novel synthesis of 3,6-disubstituted-1,2,4,5-tetrazine derivatives from hydrazones by using [hydroxyl(tosyloxy)iodo]benzene
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A mild and efficient protocol for the construction of 1,4-dihydro-3,6- disubstituted-1,4-bis(p-toluenesulfonyl)-1,2,4,5-tetrazines from p-toluenesulfonyl hydrazones mediated by [hydroxyl(tosyloxy)iodo]benzene in the presence of pyridine has been developed. This protocol affords the products in good to excellent yields. The corresponding 3,6-disubstituted-1,2,4,5-tetrazines can be easily obtained through one-step N-deprotection of p-toluensulfonyl groups and aromatization by tetrabutyl ammonium fluoride in THF. A mechanism has been proposed.
- Liu, Haixuan,Wei, Yunyang
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supporting information
p. 4645 - 4648
(2013/08/23)
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- Synthesis, structures of some unsymmetrical 3,6-disubstituted-1,2,4,5- tetrazines
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(Chemical Equation Presented) A series of new unsymmetrical 3-phenyl-6-benzyl-1,2,4,5-tetrazine derivatives 10a-i were synthesized and characterized by IR, NMR, MS, and element analysis. The structures of 4a, 10c, 10d and 10h were analyzed by X-ray crystallography, which had intermolecular C-H...N, C-H...Cl, C-H...Π and Π...Π H interactions.
- Hu, Wei-Xiao,Xu, Feng
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experimental part
p. 1745 - 1750
(2009/05/31)
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- Diazocinones: Synthesis and conformational analysis
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1,2,4,5-Tetrazines (prepared from aryl nitriles) condense with isoxazolylcyclobutanones (prepared from 3-benzenesulfonyl-3-vinylcyclobutanol) in methanolic KOH to give conformationally restricted 6-isoxazol-5-yl-6,7- dihydro-5H-[1,2]diazocin-4-ones. The s
- Robins, Lori I.,Carpenter, Richard D.,Fettinger, James C.,Haddadin, Makhluf J.,Tinti, Dino S.,Kurth, Mark J.
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p. 2480 - 2485
(2007/10/03)
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- Synthesis, structure analysis, and antitumor activity of 3,6-disubstituted-1,4-dihydro-1,2,4,5-tetrazine derivatives
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Fourteen compounds of 3,6-disubstituted-1,4-dihydro-1,2,4,5-tetrazine derivatives were prepared and their structures were confirmed by single-crystal X-ray diffraction and the semi-empirical calculation of PM3 method. This reaction yields the 1,4-dihydro derivatives rather than the 1,2-dihydro derivatives. The central six-membered ring of 1,4-dihydro-1,2,4,5-tetrazine has a chair conformation and therefore is not homoaromatic. Their antitumor activities were evaluated in vitro by SRB method for A-549 and BEL-7402 cells, and MTT method for P-388 and HL-60 cells. The results show that there is one compound which is highly effective against P-388 cells and one compound which is highly effective against HL-60 cells. So it is a kind of compound which possesses potential antitumor activities and is worth to research further.
- Rao, Guo-Wu,Hu, Wei-Xiao
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p. 3702 - 3705
(2007/10/03)
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- Synthesis and antitumor activity of s-tetrazine derivatives
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Fifty-five compounds of s-tetrazine derivative including hexahydro-, 1,6-dihydro, 1,4-dihydro-, 1,2-dihydro- and aromatic s-tetrazine were prepared. Their antitumor activities were evaluated in vitro by MTT method for P-388 cell and SRB method for A-549 cell. The results show that there are 9 compounds which in 10-6 μM have more than 50% inhibition rate to A-549 cancer cell growth, and 7 compounds in 10-6 μM have more than 50% inhibition rate to P-388 cancer cell growth. The IC50 of compound 3q for P-388, Bel-7402, MCF-7 and A-549 are 0.6 μM, 0.6 μM, 0.5 μM and 0. 7 μM, respectively. So s-tetrazine derivative is a kind of compound which possesses potential antitumor activities and is worth to research further.
- Hu, Wei-Xiao,Rao, Guo-Wu,Sun, Ya-Quan
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p. 1177 - 1181
(2007/10/03)
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- Tetrazoles: XLIV. Synthesis and chemical properties of 5-substituted 2-triphenylmethyltetrazoles
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Tritylation of tetrazole and its 5-substituted derivatives with triphenylmethyl chloride under conditions of phase-transfer catalysis regioselectively yields the corresponding 5-substituted 2-trityltetrazoles which can be used to protect N-H bonds in nitrogen-containing heterocycles and O-H bonds in primary alcohols. Thermolysis of 2-trityltetrazoles in benzonitrile leads to 3,6-disubstituted 1,2,4,5-tetrazines. Thermal transformation of the same compounds in dodecane follows a radically different mechanism, resulting in formation of difficultly accessible 8,8-diphenylheptafulvenes. The structure of the latter was proved by X-ray analysis.
- Myznikov,Artamonova,Bel'skii,Stash,Skvortsov,Koldobskii
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p. 1360 - 1369
(2007/10/03)
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- BADANIA W DZIEDZINIE TIOAMIDOW I ICH POCHODNYCH IX. SYNTEZA POCHODNYCH 1,2,4,5-TETRAZYNY
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In reactions of N,N-disubstituted thioamides, derivatives of 4-thiobenzoylmorpholine, 1-thiobenzoylpiperidine and N1,N2-di(α-morpholinobenzylidene)azine, N1,N2-di(α-piperidinobenzylidene)azine also 4-(R-α-phenylaminobenzylidene)morpholinium and 1-(R-α-phenylaminobenzylidene)piperidinium iodides with hydrazine there was obtained a series compounds, derivatives of 1,2,4,5-tetrazine.Structures of obtained compounds have been determined by elemental analysis and on the ground of their UV and IR spectra.
- Santus, Maria
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p. 183 - 188
(2007/10/02)
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- The Role of Lithium Amides as Reducing Agents in a Novel Pathway to 3,6-Diarylpyridazines by Ring Transformations of 3,6-Diaryl-s-tetrazines
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3,6-Diaryl-s-tetrazines undergo two competing reactions when treated with lithium amides.The first, direct nucleophilic attack and addition of lithium amide to the tetrazine, appears to be predominant when a less hindered amide is used, and moderate quantities of tetrazine are then regenerated on quenching.The competing reaction, which is seen more clearly with a bulkier amide such as lithium di-isopropylamide, involves reduction of tetrazine to a dihydro derivative with concomitant formation of imine from the amide: this imine is then attacked by further amide and gives rise to a charged intermediate which reacts with more tetrazine to form a pyridazine.
- Hunter, Daniel,Neilson, Douglas G.
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p. 1601 - 1603
(2007/10/02)
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- Aryl s tetrazines with antiinflammatory activity
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Various aryl s tetrazines and benzyl s tetrazines displayed aspirin like activity when tested against carrageenan induced edema in the rat, uv induced erythema in guinea pigs, and adjuvant induced arthritis in rats. These agents also displayed analgesic activity in the mouse writhing and paw pain tests but also lowered the red blood cell count in normal healthy rats.
- Lang Jr.,Johnson,Cohen,et al.
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p. 1404 - 1409
(2007/10/07)
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