1.3.5- Triazines nucleophilic reactions

Triazine-3,5-dione, 6-bromo-debromination, 3, 416 nucleophilic reactions, 3, 417... 

Base-catalyzed hydrogen exchange, 16, 1 Basicity and acidity of azoles, 41, 187 Behavior of monocyclic 1,2,4-triazines in reactions with C-, N-, O-, and S-nucleophiles, 46, 73 1-, 2-, and 3-Benzazepines, 17, 45 Benzisothiazoles, 14, 43 38, 105 Benzisoxazoles, 8, 277 29, 1 Benzoazines, reactivity with nucleophiles,... 

A readily realizable synthesis of the quinazolin-4(3//)-one ring system 22 is the reaction of anthranilic acid or methyl anthranilate and their derivatives 20 with 1,3,5-triazine. The reaction proceeds via the intermediacy of 21 which results from the nucleophilic attack of the amino group of 20 on an electrophilic carbon atom of 1,3,5-triazine. ... 

Behavior of Monocyclic 1,2,4-Triazines in Reactions with C-, N-, O-, and S-Nucleophiles... 

The usual nucleophilic substitution of substituents directly bound to the heterocyclic ring was observed for monocyclic and condensed 1,2,3-triazines. These reactions may be accompanied by a ring opening of the 1.2,3-triazine ring after the nucleophilic attack at the 4-position. 1,2,3-Benzotriazines and monocyclic 1,2,3-triazines seem to be less stable than 1,2,3-triazines condensed with heterocycles. 

Nucleophilic displacement of chlorine, in a stepwise manner, from cyanuric chloride leads to triazines with heteroatom substituents (see Section 6.12.5.2.4) in symmetrical or unsymmetrical substitution patterns. New reactions for introduction of carbon nucleophiles are useful for the preparation of unsymmetrical 2,4,6-trisubstituted 1,3,5-triazines. The reaction of silyl enol ethers with cyanuric chloride replaces only one of the chlorine atoms and the remaining chlorines can be subjected to further nucleophilic substitution, but the ketone produced from the silyl enol ether reaction may need protection or transformation first. Palladium-catalyzed cross-coupling of 2-substituted 4,6-dichloro-l,3,5-triazine with phenylboronic acid gives 2,4-diaryl-6-substituted 1,3,5-triazines <93S33>. Cyanuric fluoride can be used in a similar manner to cyanuric chloride but has the added advantage of the reactions with aromatic amines, which react as carbon nucleophiles. New 2,4,6-trisubstituted 1,3,5-triazines are therefore available with aryl or heteroaryl and fluoro substituents (see Section 6.12.5.2.4). 

Cyanuric fluoride behaves much the same as cyanuric chloride but its higher reactivity leads to nucleophilic reactions with aromatic amines, which act as carbon nucleophiles. This is a useful advantage for cyanuric fluoride, as a synthetic reagent, for the synthesis of these triazine derivatives with carbon substituents. 

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