1.3.5- Triazines, synthesis

H-Cyclohepta[e][l,2,4]triazine, 3-phenyl-synthesis, 3, 449 Cyclohepta[e][ 1,2,4]triazines synthesis, 3, 453 Cyclohepta[e][l,2,4]triazinone reactions... 

Hsynthesis from, 3, 767 Indenobenzazepines pharmacological properties, 7, 546 Indenone oxide, 2,3-diphenyl-photochromic compound, 1, 385 In deno[ 1,2-c][ 1,2,4]triazines synthesis, 3, 434 Indicated hydrogen nomenclature, 1, 33 Indigo, I, 317, 318-319, 4, 370 Baeyer synthesis, 1, 319 colour and constitution, 1, 344-345 molecular structure, 4, 162 photochromic compound, 1, 386 synthesis, 4, 247 Indigoid dyes... 

Naphtho[2,l-e][l,2,4]triazine-l-carboxylic acid, 3-0X0-1,4-dihydro-synthesis, 3, 453 Naphthotriazines betaines synthesis, 2, 69 N aphtho-1,2,4-triazines synthesis, 3, 445 Naphtho[ 1,2- e][ 1,2,4]triazines synthesis, 3, 433 Naphthop, 1 -e][l, 2,4]triazines synthesis, 3, 433... 

Phenanthro[l,2-d][l,2,3]selenadiazole, 10,11 dihydro- H NMR, 6, 348 synthesis, 6, 353 Phenanthro[b]thiophenes synthesis, 4, 914 Phenanthro[4,5-bcd]thiophenes synthesis, 4, 883, 907, 914 Phenanthro[9,10-ej[l, 2,4]triazines synthesis, 3, 434 Phenarsazin synthesis, 1, 561 Phenazine dyes, 3, 196-197 nitration, 3, 177 UV Spectra, 2, 127 Phenazine, 3-amino-2-hydroxy-in colour photography, 1, 374 Phenazine, 1-chloro-nucleophilic substitution, 3, 164-165 5-oxide... 

Selenazolium hydroxide, anhydro-4-hydroxy-2,3,5-triphenyl-synthesis, 6, 343 Selenazolo[3,2-b][ 1,2,4]triazine synthesis, 6, 347... 

Traube purine synthesis, 423 Triamcinolone, 201 Triamcinolone acetonide, 201 Triamterine, 427 Triazines, synthesis, 280 Triazolam, 368 Trichlomethiazide, 359 Trichomonas, 238 Tricyclic antidepressants, 149 Trifluoperidol, 306 Trifluoromethyl group, potentiation of biologic activity, 380 Triflupromazine, 380, 381 Trihexyphenidil, 47 Triiodothyronine, 95 Trimeprazine, 378 Trimethadione, 232 Trimethobenzamide, 110 Trimethoprim, 262 Trioxsalen, 334 Tripelenamine, 51 Triprolidine, 78 Tropinone, 5 Tropocaine, 7 Truth serum, 274... 

Tebbe reaction 148 Tetracyclin synthesis 190 Tetrazole synthesis 17 Tetrodotoxin synthesis 136 Tocopherol synthesis 142 Tonantzitlolone synthesis 188 Triazine synthesis 17 Triclavulone synthesis 102... 

Aryl cyanates (cyanic esters), which can be prepared in situ (67AG(E)206), form 1,3,5-triazines under either acid or base catalysis (Scheme 83) (77RCR278, 78RCR975). The acid-catalyzed reactions are not properly understood, but it seems that the mechanism is dependent on the precise nature of the Lewis acid used. Yields are usually good (Table 14). The reaction of aryl cyanates with ketoximines yields 1,3,5-triazines (146) via the intermediate (145) (Scheme 84) (66CB2361). Alkyl cyanates are very reactive, and isomerize readily therefore they are unsuitable starting materials for 1,3,5-triazine synthesis. 

It is curious that there have been more fundamental developments in 1,3,5-triazine synthesis by this method than in any of the other sections, yet it is the oldest of all the synthetic routes. Cyanuric acid was originally prepared by the pyrolysis of uric acid (7) (see Section 2.20.1.2). The mechanism was proposed by Brandenberger and coworkers on the basis of isotopic labelling studies, and was reviewed by Modest (B-61MI22000, p. 706). The rearrangement of pyrimidines to 1,3,5-triazines is the most important advance in this area. 

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