1.2.4- Triazine, trifluoro-, nucleophilic substitution

Barlow, M.G. Haszeldine, R.N. Simon, C. Simpkin, D.J. Preparation and some nucleophilic substitution reactions of trifluoro-l,2,4-triazine. J. Chem. Soc., Perkin Trans. 1 1982, 1251-1254. 

Barlow M, Haszeldine R, Simon C, SimpMn D, Ziervogel G (1982) Heterocyclic polyfluoro-compounds. Part 39. Preparation and some nucleophilic substitution reactions of trifluoro-1,2,4-triazine. J Chem Soc PerMn Trans 1 1251-1254... 

Nucleophilic aromatic substitution reactions follow the well-established two-step addition-elimination mechanism via a Meisenheimer intermediate (Fig. 8.3). Indeed, reaction of fluoride ion with trifluoro- -triazine, gives the corresponding perfluorocarbanion system that has been directly observed by NMR spectroscopy, supporting this mechanistic rationale. This reactivity has been termed mirror-image chemistry, which contrasts the very well-known chemistry of... 

It is worth noting that 2,4,6-trifluoro-l,3,5-triazine 55 is less active than cyanuric chloride in the reaction of with aniline (Scheme 49) [84]. N,N-Dimethylaniline and l,8-bis(dimethylamino)naphthalene react with cyanuric fluoride 55 as C-nucleophiles to give 2,4-difluoro-6-(4-dimethylaminophenyl)-l,3,5-triazine 119 and l,8-bis(dimethylamino)-4,5-(2,4-difluoro-l,3,5-triazinyl-6)naphthalene 123 (Scheme 49) [8], Contrary to it, N,N-diethylaniline, and ortho- or para-substituted N,N-dimethylanilines react with trifluoro-l,3,5-triazine 55 as N-nucleophiles. These reactions are accompanied by elimination of N-alkyl group and the formation of 2,4-difluoro-6-arylamino-l,3,5-triazines 120-122 (Scheme 49). 

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