1.2.4- Triazines derivatives

Research on symmetrical triazine derivatives and the screening of these as herbicide compounds began in Bern in 1952 in the research laboratories of the Swiss company Geigy. This was the work that led to the development of one of the most important groups of herbicides known today, the triazine herbicides. 

The first publication on this work, describing 2-chloro-4,6-bis(diethylamino)-s-triazine and its herbicidal effect, appeared in 1955 (Cast, et al, 1955). This compound (chlorazine), which is effective against mono- and dicotyledons, acts by absorption through the leaves. However, its selectivity is rather poor, and it was not put on the market. 

Kniisli and Gysin reported on 2-chloro-4,6-bis(ethylamino)-.r-triazine (simazine), one of the most important triazine herbicides even today (Cast et ai, 

Since the discovery of triazine herbicide a great number of triazine compounds have been synthesised, primarily by the Geigy Co. (now Ciba-Geigy AG) but more recently by other international concerns as well. As a result, about 20 different herbicidally active 5-triazines are available today on the international market. It is estimated that in 1980 i-triazine derivatives accounted for 20-25% of the world production of herbicidally active substances. 

Several thousand publications have dealt with the herbicidal activity, mode of action, metabolism, absorption mechanism, biological and nonbiological detoxication and persistence of 5-triazine derivatives. 

4-dihydro-derivative which rearranges to a 4,5-dihydro-compound. The latter can be further reduced to an imidazolone or to a tetrahydro-1,2,4-triazin-3-one. 

The preparation of hexahydro-1,3,5-triazines (394) from paraformaldehyde and methanesulphonamide or ethyl carbamate has been reported. l,3-Dinitro-5-nitroxymethylperhydro-l,3,5-triazine (395b) is a postulated 

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A large number of hindered phenoHc antioxidants are based on the Michael addition of 2,6-di-/ f2 -butylphenol and methyl acrylate under basic catalysis to yield the hydrocinnamate which is a basic building block used in the production of octadecyl 3-(3,5-di-/ f2 butyl-4-hydroxyphenyl)propionate, [2082-79-3], tetrakis(methylene-3(3,5-di-/ f2 butyl-4-hydroxylphenyl)propionate)methane [6683-19-8], and many others (63,64). These hindered phenolic antioxidants are the most widely used primary stabilizers in the world and are used in polyolefins, synthetic and natural mbber, styrenics, vinyl polymers, and engineering resins. 2,6-Di-/ f2 -butylphenol is converted to a methylene isocyanate which is trimerized to a triazine derivative... 

This reactivity of A-unsubstituted amino-pyrazoles and -indazoles which can be regarded as 1,3-diamino derivatives has been used to build a great variety of fused six-membered heterocycles such as the 1,2,4-triazine derivatives (540) and (541), the 1,3,5-triazine derivatives (542) and (543), and benzothiadiazines (544). 

It should be stated that the nomenclature of the triazine derivatives is not uniform, e.g., in Chemical Abstracts the compounds are often indexed according to another sy.stem than that used in the original papers, and an additional system could have been used for this review. To avoid further complications, the author will u.se the commonest nomeclature in accordance with the representative monographs in this field (see references 12 and 45.)... 

Its oxidation to cyanuric acid (10) and its hydrolysis to biuret (11) and formic acid is also in agreement with the new formulation of allantoxaidine as a triazine derivative. A very strained explanation would be required to make these reactions conform to the original structure. 

The chemistry of the 6-aza analogs of pyrimidine bases which has been developed from the biochemical aspect since about 1956 was based on work reported in relatively numerous older papers. In spite of the fact that 6-azauracil was prepared only in 1947 and suitable syntheses were described only quite recently, substances of this type and methods of their preparation had been known for a long time. The chemistry of 6-aza analogs of pyrimidine bases is therefore relatively closely linked with the chemistry of the 1,2,4-triazine derivatives. 

In a preliminary communication, the dihydroxy-1,2,4-triazine derivative 163 has been assigned the structure shown on the basis of infrared evidence. The pK and ultraviolet and infrared spectral data support the formulation of 6-azauracil (164) as a dioxo compound. 

Data by Matsui et and Goi for the reactions of chloro-s-triazine derivatives of series 51 and 52 are assembled in Table XIV. 

Effect of Some Nitrogen-, Oxygen-, and Sulfur-Containing Groups on the Rate Constants for the Reaction of Chloro-s-triazine Derivatives with Various Nucleophiles... 

UV absorbers have been found to be quite effective for stabilization of polymers and are very much in demand. They function by the absorption and harmless dissipation of the sunlight or UV-rich artificial radiation, which would have otherwise initiated degradation of a polymer material. Meyer and Geurhart reported, for the first time in 1945 [10], the use of UV absorber in a polymer. They found that the outdoor life of cellulose acetate film was greatly prolonged by adding phenyl salicylate (salol) [10]. After that, resorcinol monobenzoate, a much more effective absorber, was introduced in 1951 [11] for stabilization of PP, but salol continued to be the only important commercial stabilizer for several years. The 2,4-dihydroxybenzophenone was marketed in 1953, followed shortly by 2-hydroxy-4-methoxybenzophenone and other derivatives. Of the more commonly known UV absorbers, the 2-hydroxybenzophenones, 2-hy-droxy-phenyl-triazines, derivatives of phenol salicylates, its metal chelates, and hindered amine light stabilizers (HALS) are widely used in the polymer industry. 

Following is a schematic illustration of how triazine derivatives form covalent bonds with cellulose fibers ... 

Amination of triazine derivative 412, obtained from 411, with propar-gylamine gave 413, which was cyclized to give (89CZ252) imidazotriazine 414 (Scheme 90). 

Alkylation of chlorotheophylline with chloroacetonitrile gave 608 and cyclization with hydrazine gave [88CI(L)785] triazine derivative 609. Condensation of the latter with different aldehydes gave the corresponding hydrazones. 

Thiazolotriazines 636 (R = CO,Me) were prepared [84JCS(P1)2707] by cycloaddition of dimethyl acetylenedicarboxylate with triazine derivative 632. Derivatives of thiazolo[3,2-b][l,2,4]triazin-3,7-diones 637 have been formed (74JPR163) on reaction with aromatic aldehydes and diazonium salts to give 636 (R = Ar) and 638, respectively. Regioselective catalyzed... 

The benzo analogue 684 of [1,2,4]triazino[3,2-6]thiazoles was prepared (88LA1089) by heating triazine derivative 632 with 2,4-dinitrochloroben-zene or picryl chloride in N,N-dimethyl formamide (Scheme 143). 

The sequential treatment of triazine derivative 990 with acyl chlorides and acetic anhydride and perchloric acid afforded (86H1031) thiadi-azolo[l, 2,4]triazinium perchlorates 991. On the other hand, cyclocondensation of 992 with organic acids gave 993 [82JHC1577 83JAP(K)58/180492] and 994 with aromatic aldehydes (84JIC552) (Scheme 183). 

Pyrimido[5, 4 4,5]pyrazolo[3,2-c][l,2,4]triazine derivatives 1049and 1050 were prepared by treatment of diazo compound 1048, prepared from 1047, with pentane-2,4-dione and ethyl acetoacetate, respectively [92JCS(Pl)239]. 

Sauer and Heldmann [97] recently reported an interesting application of ethynyltributyltin as an electron-rich dienophile in an inverse electron-demand Diels-Alder reaction with the electron-deficient triazine derivative 94. This method is interesting because the reaction is highly regioselective and the trialkylstannyl group is easily replaced by several groups under mild conditions, leading to substituted pyridines 95 (Scheme 2.41). 

A. T. Au and H. F. Hussey. Method of inhibiting corrosion using perhydro-S-triazine derivatives. Patent US 4830827, 1989. 

Kreuxzberger, A. Reactions of Trichloromethyl-1.3.5-triazine Derivatives with Amines. J. Amer. chem. Soc. 79, 2629 (1957). 

Lipophilicity and specific hydrophobic surface area were determined by using reversed-phase thin-layer chromatography for fused heterocyclic ring systems including five pyrido[2,iy][l,2,4]triazine derivatives <1998MI64>. 

An unexpected ring formation involving a ring transformation occurred in the reaction of the pyrido[l,2- ]-[l,2,4]triazine derivative 101 with dimethyl acetylenedicarboxylate, and tricyclic compounds 102 were obtained in high yields (Equation 10) <2001JHC205>. 

Most of the reported triazinothiadiazines have been prepared from 1,2,4-triazine derivatives. Treatment of amino-1,2,4-triazine 28 with chloroacetyl chloride in dioxane in the presence of triethylamine at 10 °C resulted in the formation of 6-methyl-4-(A -chloroacetamido)-3-thioxo-5-oxo-2,3,4,5-tetrahydro-l,2,4-triazine 29 and 3-methyl-4,7-dioxo-4,6,7,8-tetrahydro-l,2,4-triazino[3,4-A][l,3,4]thiadiazine 15 (Scheme 1) <2005JHC935>. 

Benzonitrile is also trimerized to the s-triazine derivative by Raney nickel242 in a reaction which may proceed via the coordination compound (148)243 in a separate experiment this complex reacts with benzonitrile in the presence of benzamide to give the trimer (Scheme 171)242... 

The reaction of 1,2,3-triazolium-l-aminides 3 with propiolate esters led to fluorescent 2,5-dihydro-1,2,3-triazine derivatives 4 in one pot, involving a Huisgen cycloaddition followed by a sequence of rearrangements <06JOC5679 06TL1721>. These reactions can be carried out in acetone, in water, or under solvent-free conditions. 

Nonmesomorphic as well as mesomorphic F-shaped acids with a structure similar to banana liquid crystals, have been complexed to a 2,4,6-triamino-l,3,5-triazine derivative <06JA4487>. 

Pyrazolo[4,3-e][l,2,4]triazine derivatives have been prepared from oximes of 5-aryl- and 5-formyl-l,2,4-triazines <06MI191 >. Novel pyrazolo[5,1 -c][ 1,2,4]triazines incorporating an Af-(2-oxoethyl)phthalimide moiety have been reported <06JCR(S)6>. 

Aminomethylation of 2-ami no-5,5-bis(hydroxymcthyl)-l,3-thiazol-4(5//)-onc and its spiro analogs gave the corresponding [l,3]thiazolo[3,2-o][l,3,5]triazine derivatives <06CHE1086>. 

Reactive halogen crosslinkers are mainly specific for sulfhydryl groups at physiological pH, however at more alkaline pH values they can readily cross-react with amines and the imidazole nitrogens of histidine residues. Some reactivity with hydroxyl-containing compounds also may be realized, particularly with dichloro-s-triazine derivatives under alkaline conditions. 

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