1.2.4- Triazine, 3,5,6-trichloro-, -trifluoro

Trifluoro-l5355-Triazine. Cyanuric fluoride can be produced from 2,4,6-trichloro-j -l,3,5-triaziae [108-77-0] (cyanuric... 

Addition of cyclopentene to trifluoro-1,2,4-triazine gave products arising from addition of a second molecule of olefin. This was in contrast to trichloro-l,2,4-triazine where the eventual products were predominantly pyridine derivatives [82JCS(P1)1245]. 

Trichloro-l,3.5-triazine (cyanuric chloride, 5) can be converted using a sixfold excess of sulfur tetrafluoride at 250 C into 2,4,6-trifluoro-l,3,5-triazine (cyanuric fluoride, 6) with lower proportions of sulfur tetrafluoride, cyanuric chlorofluorides are formed.191... 

Method A 4 Cl2 was passed through SbF3 (100g, 0.54mol) at 100"C until no more Cl2 was absorbed. The SbF3Cl2 which formed was allowed to cool to rt and 2,4,6-trichloro-l, 3,5-triazine (1 50 g. 0.26 mol) was added. The reaction flask was fitted with a 30-cm Vigreux column and the flask was heated until all the liquid product had distilled. Redistillation of the liquid product gave 2,4,6-trifluoro-l, 3,5-triazine (2) as a colorless liquid yield 26.1 g (71 %) bp 74 C. 

Trifluoro-l,3,5-triazine (13) is prepared from 2,4,6-trichloro-l,3,5-triazine (12) and sodium fluoride in refluxing tetramethylene sulfone and distilling out the product as it is formed (bp 72.5-73.5cC/760 Torr).11... 

Silver(I) fluoride is most useful for the conversion of 2-chloro-4,6-bis(pentafluoroethyl)-1,3,5-triazine, 2-chloro-4,6-bis(heptafluoropropyl)-l,3,5-triazine, and 2,4,6-trichloro-l,3,5-triazine to the corresponding fluoro-l,3,5-triazines. 2-Fluoro-4,6-bis(pentafluoroethyl)-l,3,5-triazineis obtained in 98 % yield, and 2-fluoro-4,6-bis(heptafluoropropyl)-l,3,5-triazinein 95 % yield, (both at 90 C for 30 minutes), while 2,4,6-trifluoro-l,3,5-triazine is available in 78.5% yield (at 100CC for 1 hour). Silver(II) fluoride, mercury(II) fluoride and antimony dichloride trifluoride give lower yields of these compounds.34... 

Trichloro-l,2,4-triazine (73) reacts with potassium fluoride to give the trifluoro compound (325). This reacts with hexafluoropropene to give 5-heptafluoroisopropyl-3,6-difluoro- (326), 3,5-bis(heptafluoroisopropyl)-6-fluoro- (327) and a small amount of 5,6-bis(heptafluoroisopropyl)-3-fluoro-l,2,4-triazine (328) and finally to the... 

Condensed pyridines were obtained when 1,2,4-triazines reacted with cyclic alkenes. Trichloro-l,2,4-triazine (73) afforded the condensed pyridines (370a, b) in high yield with cyclopentene and (Z)-cyclooctene, respectively. In the reaction with cyclopentene the bis adduct (371) was isolated in small amount but the bis adduct (372a) is the sole reaction product when (73) is treated with norbornene. The more reactive trifluoro-1,2,4-triazine (325) affords bis adducts (371b, c 372b) with cyclopentene and (Z)-cyclooctene as well as with norbornene (79CC658). 

Trifluoro-l,2,4-triazine (106) behaves similarly to the trichloro compound toward nucleophilic reagents, but is more reactive. When treated with methanol at room temperature it gives a mixture of 5,6-di-methoxy-3-fluoro-l,2,4-triazine (109) and 3,5-dimethoxy-6-fluoro-l,2,4-triazine (110) in the ratio 2 1 (82JCS(P1)1251). Reactions of 106 with di-... 

Trichloro-s-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 prepared by adding one mole of three different amines to the reaction mixture at each of the three temperatures. The tribromo analog is stated to react more rapidly than cyanuric chloride with ammonia or primary and secondary amines. Toward ammonia, methoxide ion, or water, the trifluoro analog is also qualitatively more reactive with ammonia (0°, 1 hr) mono-amination occurred in ether and di-amination in tetrahydrofuran. ... 

Thus, 3,5,6-trichloro-l,2,4-triazine affords the condensed pyridines 6 in high yield when reacted with cyclopentene (77%) or (Z)-cyclooctene (80%), respectively387 (see Houben-Weyl, Vol. E7b, p 476 ff). In the reaction with cyclopentene the bisadduct 7 is isolated in small amounts. The bisadduct is the sole product when the trichloro compound is reacted with bicyclo[2.2.1]hept-2-ene. The more reactive 3,5,6-trifluoro-l,2,4-triazine affords the bisadducts with cyclopentene and (Z)-cyclooctenc as well as with bicyclo[2.2.1]hept-2-ene, e.g. formation of 8 (X = F).385... 

To sulfolane (tetrahydrothiophene 1,1-dioxide 930 g) heated up to 60"C, were added pulverized NaF (360 g, 8.6 mol) and 2,4,6-trichloro-l,3,5-triazine (1 450 g, 2.44 mol). The mixture was stirred and heated to 75 C to initialize the reaction. The temperature was then raised to about 120 "C so that the 2,4.6-triflu-oro-l,3,5-triazine formed could begin to distill off further heating to 220X caused the product to distill over completely. N2 gas bubbled into the distillation flask evaporated the residual 2,4,6-trifluoro-l,3,5-tri-azine yield 286 g (86.8%) bp 70-74 X. The distillation residue was 1460 g of a suspension of NaCl in sulfolane, which contained HF and partially fluorinated triazines. 

Gas-phase IR spectra of 4,5,6-trifluoro- and 5-bromo-4,6-difluoro-l,2,3-triazine have been recorded, while KBr as matrix was used for 4,6-difluoro-5-iodo-, 4,5,6-trichloro-, and tribromo-l,2,3-triazine <1998TH1>. Slightly different frequencies had been reported earlier for the trichloro compound <1979CB1529>. IR data from KBr disks or liquid films of 1,2,3-triazines with various dialkylamino substituents have been reported <1979CB1529>, and IR frequencies of the following compound types are also available 2-oxides of alkylated and arylated 1,2,3-triazines... 

The reaction of 4,5,6-trichloro-l,2,3-triazine 4 with potassium fluoride at an elevated temperatures provides fully substituted 4,5,6-trifluoro-l,2,3-triazine 2 in addition to compounds 5 and 6 with partial displacement of chlorine atoms (Scheme 7) [11], It is clear that yields of fluorinated products depend on the reaction conditions (Table 3) [11]. At temperatures of 150-200 °C replacement of one or two chlorine atoms take place. The polyfluorinated 1,2,3-triazines 2, 5 were obtained when using two-step process in 55-69 % yields. 

Another example illustrating utility of this approach is displacement of chlorine atoms in 3,5,6-trichloro-l,2,4-triazine which does occur in a melt of compound 17 with dry KF (Scheme 12) [20]. The conversion degree depends on the reaction conditions at450 °C the dominantproduct of the reaction proved to be 3,5,6-trifluoro-1,2,4-triazine 18, while 3-chloro-5,6-difluoro-l,2,4-triazine 19 was isolated as a minor product. 

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