1,3,5-Triazines moiety

Drew, M.G.B., Hill, C., Hudson, M., Iveson, P.B., Madic, C., Youngs, T.G.A. 2004. Solvent extraction and lanthanide complexation studies with new terdentate ligands containing 1,3,5-triazine moieties. Journal of the Chemical Society, Dalton Transactions 2 244-251. 

The chemistry of 1,3,5-triazine did not find a significant development in 2013. There were few examples of new synthetic methods. However, the 1,3,5-triazine moiety still attracts a great deal of attention as a basis for construction of new materials and compounds with different useful properties from biological activity to liquid crystals. Here we have coUected some outstanding examples. 

Another special feature connected with the 1,3,5-triazine moiety is spontaneous formation of a long-lived glassy state, by bisarylamino-1,3,5-triazines. A wide series of differently substituted derivatives 49 was synthesized by nucleophilic substitution of chlorine atoms in cyanuric chloride 20 with methylamine in the first step and then two equivalents of substituted aniline in the second step (13NJC3881). 

A large number of 1,2,4-triazines that are condensed with one or more heterocycles are well known and a wide variety of synthetic methods for their preparations are available. Compounds containing the 1,2,4-triazine moiety are in use as pharmaceuticals, dyes, pesticides, herbicides, etc., and a great number of reports have been directed to the synthesis of the title heterocycles having potentially useful biological properties. 

The radical anions of 309, 311 (Me derivative of enol), and 308 were generated electrochemically ESR spectroscopy indicated that the unpaired electron was delocalized in the triazine moiety (81MI3). 

In a similar manner, starting from 2-methylchloride-naphtho[l,8-de][l,2,3]triazine and magnesium, via a novel sonication-promoted Barbier reaction, an a-aminomethyl carbanion equivalent is generated which reacts in situ with a variety of carbonyl compounds. Subsequent catalytic hydrogenolysis of the triazine moiety yields the corresponding amines <00TL4685>. Sterically controlled regiospecific cyclization of aldose-5-ethyl-l,2,4-... 

The structures of several compounds containing the pyrrolo[l,2,4]triazine moiety have been established by X-ray crystallography, as for example pyrrolo[l,2- ][l,2,4]triazine 13 <1997J(P1)1829>, 4-acetyl-l-phenyl-2a,3,5-triaza-benz[r-,<7]azulene 14 <2000H(53)323>, heterodiquinane 15 <1998CL1135>, cation 16 derived from methylation of 3-phenylcyclohepta[4,5]pyrrolo[l,2- ][l,3,5]triazine-2,4(377)-dione <2005H(65)1629>, 2-phenyl-3-phenyl-... 

Finally, the pyrrolo[2,l-/ [l,2,4]triazine moiety was also encountered in azulene derivatives. Reactions of l,8-diamino-3-phenyl-l-azaazulenium salt 54 with triethyl orthoformate and acetic anhydride gave l-phenyl-2a,3,5-mjzjbenzb. //]jzulcncs 55 and 56. The reaction of the same salt with ethyl pymvate gave 4-acetyl-l-phenyl-2a,3,5-triazabenz[c, /]azulene 14 <2000H(53)323>. 

It is also possible to carry out the ring closure of the triazine moiety, and such a reaction was already concisely mentioned in CHEC-II(1996) <1996CHEC-II(8)445>. Transformation of 363 to 364 reported by Costanzo et al. <1999JME2218> also belongs to this type of cyclization. 

A novel photoactive thermally stable polymer (xv) containing the triazine moiety has been synthesized by Khoee and Zamani [27] by the reaction of A,A-(4,4 -oxy bis (4,l-phenylene))-bis-(l,3-dioxo-l,3-dihydroisobenzofuran-5-carboxamide) and A-(4,6-diamino-l,3,5-triazin-2-yl) anthracene-9-carboxam-ide in presence of a small amount of o-cresol as a solvent under microwave condition. 

El-Gendy Z, Morsy J, Allimony H et al (2003) Synthesis of heterobicyclic nitrogen systems bearing a 1,2,4-triazine moiety as anticancer drugs part IV. Phosphorus Sulphur Silicon Relat Elements 178 2055-2071... 

Another important attribute of a HALS is its effect on the thermo-oxidative stability of polypropylene multifilaments. This property is important in certain end-use applications where elevated temperature over a period of time is experienced, such as in automobile rear shelf fabrics. The excellent performance of the oligomeric HALS 4 and 6, as determined by 120°C oven aging, is shown in Figure 2. The superior activity of these products may be due not only to their low volatility but also to the presence of a triazine moiety in the structure, which appears to have a positive effect on the thermo-oxidative stability of polypropylene. 

Very few compounds containing the 1,2,4-triazine moiety are found as natural materials, such as the pyrimido[5,4-c]-1,2,4-triazines, fervenulin (2),265 reumycin (3),265 toxoflavin (4) and MSD-92 (5).441 A large number of synthetic 1,2,4-triazines have biological activity and have been used for various purposes. Thus, 1,2,4-triazines can be considered as azapyrimidines and thus a large number of 6-azapyrimidine nucleotides and nucleosides have been prepared and their properties studied intensively, for example 6-azauracil (6), 6-azathymine(7), 6-azacytosine (8), 6-azauridine (9),442 and 6-azacytidine (10).443... 

Dichlorophenyl)-l,2,4-triazine-3,5-diamine (13, Lamotrigine, LTG, BW430C, 430C78)27 and 3-amino-l,2,4-benzotriazine 1,4-dioxide (14, SR4233)440 are used as drugs. Cephalosporins and penicillins with a 1,2,4-triazine moiety have been prepared and found pharmaceutical applications.444... 

Photosensitizer-Linked Photoinitiator or Coinitiator-Based Systems Attempts have been made to incorporate the dye and the energy or the electron donor in the same molecule. An old example was apolymeric system where a morpholinoketone and a thioxanthone derivative were grafted [215]. A first recent example corresponds to a dye linked to a triazine derivative (10.61) where an intramolecular electron transfer yields a radical anion on the triazine moiety that results in the production of a radical [216,217],... 

This year the number of reports dealing with triazines has considerably decreased compared with 2003. Due to the fact that many applications of compounds bearing the triazine moiety have been reported, we have divided section 6.3.1 in two parts synthesis and reactivity and then applications. 

On the basis of the analysis of the CD spectra by the nonempirical DeVoe approach, it was possible to establish that each l-(l-naphthyl)ethylamino moiety assumes the same closed conformation with respect to the r-triazine aromatic ring (dihedral angle naphthalene-triazine, 90°), independently of the number or absolute configuration of the other l-(l-naphthyl)ethylamino groups linked to the r-triazine moiety <1998JOC8765>. 

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