1.3.5- Triazine amination

While there is clear evidence that melam Is the dimer of melamine in which two s-triazine rings are connected by a NH bridge (di 6,[2,4 diamino-1,3,5-triazine]amine) (10) ... 

When 2-phenyl-l,3,5-triazine (8) is aminated with potassium amide in liquid ammonia at - 33 C a very slow Chichibabin reaction occurs, partly via the Sn(ANRORC) mechanism and partly via the SNAE process (ratio ca. 55 45). H NMR and l5N-labelling studies have demonstrated that in solution an equilibrium exists between the starting triazine, amine adducts, open-chain amidines and triazine product 9.53... 

Aromatic /-amines can act as carbon nucleophiles in reaction with perfluorinated 1,3,5-triazines. Amines used are 1-methylpyrrole, 1-methylindole, l,8-bis(dimethylamino)naphthalene (proton sponge), A,A-dimethyl- and JV,7V-diethyl-aniline. All the amines reacted at the expected position in the ring except A,7V-diethylaniline which also gave some or//io-product not seen with N,N-dimethylaniline (Equation (8)) <92T7939>. 

A novel synthetic strategy and optical properties of highly fluorescent, triazine-amine conjugated oligomers 56 were described by Fujita and Murase. The oligomers can be expressed as (2 +l)-mer, where n represents the number of triazine rings in the oligomer (Scheme 7). 

Polyamine H —N— Amine Poly(p-dipheylether-s-triazine amine)... 

The methods described in equations 2-5 are useful in situations where the sulfonylisocyanate is not available. All of these require using a carbamate which can be prepared from the sulfonamide or heterocyclic amine with the appropriate chloroformate. In addition to the added step of chlorformate formation from phosgene and an alcohol, special care is required to prepare some of the carbamates. Although the phenyl carbamates of heterocyclic amines react, as desired, with a broad range of sulfonamides the reaction of phenyl carbamates of sulfonamides is restricted due to the failure of these interme tes to react with triazine amines. 

Furalazine, Acetylfuratrizine, Panfuran-S. Heating nitrovin in butanol or dimethylformamide at 100—130°C affords furalazine, 6-[2-(5-nitro-2-furanyl)ethenyl]-l,2,4-triazine-3-amine (34). An improved synthesis originates with 5-nitro-2-furancarboxaldehyde and acetone, proceeds through 4-(5-nitro-2-furanyl)-3-buten-2-one followed by a selenium dioxide oxidation to the pymvaldehyde hydrate, and subsequent reaction with aininoguariidine (35). Furalazine, acetylfuratrizine (36), and the A[-A/-bis(hydroxymethyl) derivative, Panfuran-S, formed from the parent compound and formaldehyde (37), are systemic antibacterial agents. 

Strong bases, such as potassium acetate, potassium 2-ethylhexoate, or amine—epoxide combinations are the most useful trimerization catalysts. Also, some special tertiary amines, such as 2,4,6-tns(A7,A7-dimethylarninomethyl)phenol (DMT-30) (6), l,3,5-tris(3-dimethylaminopropyl)hexahydro-j -triazine (7), and ammonium salts (Dabco TMR) (8) are good trimerization catalysts. 

Oligomeric hindered amine light stabilizers are effective thermal antioxidants for polypropylene. Thus 0.1% of A[,Af-bis(2,2,6,6-tetramethyl-4-piperadinyl)-l,6-hexanediamine polymer, with 2,4,6-trichloro-l,3,5-triazine and 2,4,4-trimethyl-2-pentaneainine [70624-18-9] (35) (Fig. 5), protects polypropylene multifilaments against oxidation when exposed at 120°C in a forced-air oven (22) for 47 days. 3,5-Di-/ l -butyl-4-hydroxytoluene [128-37-0] (0.1%) affords protection for only 14 days. 

Triazines substituted with amines are generally less reactive as the amine becomes more basic, and more reactive as the amine becomes less basic. The chromophore may be sufficientiy electron withdrawing or donating to affect reactivity of the dye. 

Pyrimidin-5-amine, 4-methylamino-synthesis, 3, 121 Pyrimidin-5-amine, 4-oxo-purfne synthesis from, 5, 582 Pyrimidinamines acylation, 3, 85 alkylation, 3, 86 basic pXa, 3, 60-61 diazotization, 3, 85 Dimroth rearrangement, 3, 86 electrophilic reactions, 3, 68 Frankland-Kolbe synthesis, 3, 116 hydrolysis, 3, 84 IR spectra, 3, 64 N NMR, 3, 64 nitration, 3, 69 Principal Synthesis, 3, 129 reactivity, 3, 84-88 structure, 3, 67 synthesis, 3, 129 Pyrimidin-2-amines alkylation, 3, 61, 86 basic pK , 3, 60 diazotization, 3, 85 hydrogenation, 3, 75 hydrolysis, 3, 84 mass spectra, 3, 66 Pyrimidin-4-amines acidity, S, 310 alkylation, 3, 61, 86 basic pXa, 3, 61 Schifi base, 3, 85 synthesis, 3, 110, 114 1,3,5-triazines from, 3, 518 Pyrimidin-5-amines basic pXj, 3, 61 hydrogenation, 3, 75 reactions... 

In this solvent the reaction is catalyzed by small amounts of trimethyl-amine and especially pyridine (cf. 9). The same effect occurs in the reaction of iV -methylaniline with 2-iV -methylanilino-4,6-dichloro-s-triazine. In benzene solution, the amine hydrochloride is so insoluble that the reaction could be followed by recovery. of the salt. However, this precluded study mider Bitter and Zollinger s conditions of catalysis by strong mineral acids in the sense of Banks (acid-base pre-equilibrium in solution). Instead, a new catalytic effect was revealed when the influence of organic acids was tested. This was assumed to depend on the bifunctional character of these catalysts, which act as both a proton donor and an acceptor in the transition state. In striking agreement with this conclusion, a-pyridone is very reactive and o-nitrophenol is not. Furthermore, since neither y-pyridone nor -nitrophenol are active, the structure of the catalyst must meet the conformational requirements for a cyclic transition state. Probably a concerted process involving structure 10 in the rate-determining step... 

The high reactivity of trichloro-s-triazine and tetrachloropyrimi-dine, the ease of replacement of the first chlorine atom from these compounds with several types of nucleophiles (amines, alcohols, etc.) and, finally, the important role of these reactions in dye chemistry have stimulated many investigations dealing with substituents of the general types RZ and R2Z, where Z is an electron-donor atom or group (NH, 0, S, N). 

The catalytic effect of protons has been noted on many occasions (cf. Section II,D,2,c) and autocatalysis frequently occurs when the nucleophile is not a strong base. Acid catalysis of reactions with water, alcohols, mercaptans, amines, or halide ions has been observed for halogeno derivatives of pyridine, pyrimidine (92), s-triazine (93), quinoline, and phthalazine as well as for many other ring systems and leaving groups. An interesting displacement is that of a 4-oxo group in the reaction of quinolines with thiophenols, which is made possible by the acid catalysis. 

The highly activated 2,4,6-trichloro-s-triazine with excess amines at... 

The catalytic effect of protons, of bifunctional catalysts, and of base is demonstrated in the amination of chloro derivatives of pyridazine, pyrimidine, and s-triazine (Tables V and VI). Anilino-s-triazines containing NH groups act as catalysts in their own formation. The catalytic action of protons on anhino-dechlorination of 2-chloro-4,6-diamino-s-triazine and of 2-amino-4-chloropyrimidine was reported in the classic paper by Banks. ... 

The high level of reactivity of as-triazines is also indicated by 5-substitution of 312 with ammonia or amines (110°, 20 hr, 40-65% yield) and with hydroxylamine or hydrazine (65-80°,... 

Substituents in the 6-position (cf. 267) show appreciable reactivity. 6-Bromo-as-triazine-3,5(2j, 4j )-dione (316) undergoes 6-substitution with secondary amines or hydrazine, with mercaptide anions or thiourea (78°, 16 hr), with molten ammonium acetate (170°, 24 hr, 53% yield), and with chloride ion during phosphorous oxychloride treatment to form 3,5,6-trichloro-as-triazine. The latter was characterized as the chloro analog of 316 by treatment with methanol (20°, heat evolution) and hydrolysis (neutral or acid) to the dioxo compound. The mercapto substituent in 6-mercapto-as-triazine-3,5(2iI,4if)-dione is displaced by secondary... 

Because of the ease of ring synthesis, symmetrically trisubstituted s-triazines have been more thoroughly studied, but a few nucleophilic substitutions of derivatives bearing a single leaving group are known. 2-Chloro-4,6-diphenyl- and 2-chloro-4,6-dimethyl-s-triazines (318) undergo facile nucleophilic displacements with ammonia, amines, and hydrazine, with alkoxide, or with hydrosulfide... 

Trichloro-5-triazine is mono-aminated at temperatures of — 15° to 100°, depending on the nucleophilicity of the amine and on the solvent. With ammonia and alkylamines, one chloro group is replaced at —15 to 10°, a second at 10-50°, and a third at 20-100°. Unsymmetrical triamino derivatives can be pre-... 

Azide ion is a rather weak nitrogen nucleophile, but in aqueous acetone (20°, 5 min) it readily produces 2-azido-4,6-dichloro-s-triazine (330) and also yields more slowly (0°, 12 hr, 90% yield) the 2,4,6-triazido-s-triazine. The latter is rapidly hydrolyzed (50°) to cyanuric acid and is easily mono-aminated (0°, 1 hr, in ether). 

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