Perfluoro -1,2,3-triazine

Tetrafluoro-2-azapropenylamine, formed from perfluoro-2-azapropene and ammonia, is cyclized to a triazine under moderate heating [/i95] (equation 91). 

Interaction of iV-pentafluorophenylcarbonimidoyl dichloride with benzonitrile and aluminium trichloride leads to l-pentafluorophenyl-4,6-diphenyl-13 -triazin-2-one along with urea derivatives . Reaction of perfluoro-5-azanon-4-ene with a range of bidentate nitrogen nucleophiles (urea, substituted amidine hydrochlorides and guanidine), in the presence of triethylamine or potassium hydroxide, effectively provides fluorinated 1,3,5-triazines 16-19 <00JFC(103)105>. 

Nitrosophenol (1,4-Benzoquinone monoxime), 2264 Nitrosyl chloride, 4023 Nitrosyl cyanide, 0541 Nitrosylruthenimn trichloride, 4144 NitrosylsuUuric acid, 4438 Nitrosyl tetrafluorochlorate, 3985 Perfluoro-teA-nitrosobutane, 1370 Potassimn nitrosodisulfate, 4661 Sodimn 4-nitrosophenoxide, 2181 1,3,5 -Trinitrosohexahydro-1,3,5-triazine, 1217 Trinitrosophloroglucinol, 2117... 

Analogous reactions with perfluoro(isopropyl-l,3,5-triazine) and per-fluoro(diisopropyI-l,3,5-triazine) with CsF yielded adducts 116 and 117, respectively, which were detected by 19F-NMR. Use of potassium fluoride, either alone or associated with 18-crown-6, did not lead to the formation of the adducts. In contrast, from tris(perfluoroisopropyl)-l,3,5-triazine no adduct was detected. This is quite interesting because it would indicate the importance of the gem-difluoro substitution to stabilize the adduct,160 in analogy with the effect of gem-dimethoxy substitution.76... 

Under flash vacuum thermolysis (FVT) the 1,2,3-triazine (32) was readily thermolyzed to an alkyne, a nitrile, and nitrogen in high yields. For unsymmetrically substituted 1,2,3-triazines as FVT substrates, fragmentation proceeded selectively a bulky substituent at C-4(6) made the adjacent C—N bond break more easily than the opposite C—N bond. The FVT method was applied to the synthesis of the fluorinated alkynes, perfluoro-3-methyl-l-butyne and difluoroethyne [(33), R = (CF3)2CF, F] (Equation (1)) (89CC1657, 91CC456). It has been claimed, however, that tris(dimethylamino)-1,2,3-triazine forms the monocyclic azete. 

Base-catalyzed trimerizations are facile also for example, trifluoromethyl cyanide trimer-izes in the presence of ammonia, presumably through the formation of the amidine intermediate (139 Scheme 77) (67JOC231). Similarly, perfluoro-n-propyl cyanide forms the 1,3,5-triazine in the presence of sodium methoxide, probably via the imidate (140 Scheme 78) (52JA5633). 

Perfluoroalkyl-l,3,5-triazines are very stable to oxidation and heat. They have potential as lubricating fluids for use in aerospace work (B-74MI22003). Their polymeric products are stable elastomers with excellent rubber-like properties for use as electrical wire insulation and seals for hydraulic, lubricating and fuel systems of aircraft (B-80MI22001). Perfluoro-2,4,6-tri-n-heptyl-l,3,5-triazine is a valuable reference standard for precise mass... 

Nitrosophenol (1,4-Benzoquinone monoxime), 2257 Nitrosyl chloride, 4017 Nitrosyl cyanide, 0538 Nitrosyl tetrafluorochlorate, 3979 Nitrosylruthenium trichloride, 4138 Nitrosylsulfuric acid, 4432 Perfluoro-ferf-nitrosobutane, 1366 Potassium nitrosodisulfate, 4656 Sodium 4-nitrosophenoxide, 2174 1,3,5 -Trinitrosohexahydro-1,3,5 -triazine, 1213 Trinitrosophloroglucinol, 2110... 

The ion produced by electron attachment to tris(perfluoro-n-nonyl)triazine dissociated when irradiated by light from the cw laser as shown in Figure 5 (Equation 3). 

Photolysis of perfluoro(4,6-diisopropyl)-1,2,3-triazine at 77 K gives perfluoro-2,4-diisopropylpyrazete (90JCS(P1)983, 87JCS(CC)1699). 

Thus reactions of perfluoro-2-methylpent-2-ene and perfluoro-5-azanon-4-ene with urea in the presence of triethylamine in dipolar aprotic solvents (MeCN, DMF) form 6-fluoro-4-pentafluoroethyl-5-trifluoro-methyl-l//-pyrimidin-2-one 93 and an s-triazine derivative, respectively (00JFC(103)105, 80/82JAP(K)85377). 

The interaction of perfluoro-5-azanon-4-ene with amidines and 2-amino-benzimidazole occurs with formation of a six-membered heterocycle, giving 2,4-bis(heptafluoropropyl)-6-phenyl-[l,3,5]triazine, 2,4-bis(hep-tafhioropropyl)-6-methyl-[l,3,5]triazine, and a tricyclic compound—2,4-bis(heptafhioropropyl)benz-[4,5]imidazo[l,2-tf][l,3,5]triazine (01IZY457). 

The FVT method can be applied for the synthesis of the fluorinated alkynes, perfluoro-3-methyl-l-butyne and difluoroethyne 40 (R = (CF3)2CF, F) (Scheme 3) <1989CC1657, 1991CC456>. It has been claimed, however, that tris (dimethylamino)-l,2,3-triazine forms the monocyclic azete. 

A similar approach to conferring oil-repellency on cellulose surfaces has been described using perfluoro(isopropyl-s-triazine)s [102]. 

Sigma-complexes, observed by NMR, are analagous to the well-known Wheland intermediates in hydrocarbon chemistry, is possible upon the addition of CsF to perfluoro-s-triazine derivatives [101] (Figure 4.41) but direct observation of similar o-complexes derived from less-activated perfluoroaromatic systems has not yet been reported. 

The foregoing discussion has outlined principles that can account for very wide differences in reactivities of the C—F bond. For example, while saturated perfluorocar-bons like polytetrafluoroethene are relatively inert to nucleophiles, at the other extreme are perfluoroisobutene, which reacts with neutral methanol, and perfluoro-l,3,5-triazine, which is hydrolysed in moist air. As a note of caution, great care should be taken with the systems that are very reactive to nucleophiles and correspondingly potentially very toxic, although there is no good correlation between toxicity levels and reactivity towards nucleophiles. More will be said about some of these systems in later chapters. 

Thermal properties of some other polymers containing heterocycles are reported in literature. For example, the polymers containing triazine networks substituted with perfluoro-rt-propyl or perfluoroalkyloxy groups do not decompose easily upon heating. These types of polymers are used as heat resistant oils, and several studies on their thermal decomposition are available in literature [21-23]. 

F NMR spectra for a few perfluoroalkyl-l,2,3-triazines have been reported.84 The fluorine in the 5-position of perfluoro-4,6-diisopropyl-1.2,3-triazine gives a signal at - 124.8 ppm. 

Photolysis of 3,5,6-tris[l,2,2,2-tetrafluoro-l-(trifluoromethyl)ethyl]-l,2,4-triazine gives 2,4,6-tris[l, 2,2,2-tetrafluoro-l-(trifluoromethyl)ethyl]-l, 3,5-triazine (1), perfluorobutane-nitrile, perfluoro(2,5-dimethylhex-3-yne) and nitrogen.304... 

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