Spiro triazines

In the reduction reaction of the methylpyridinium salt 20, with a variety of reagents, the novel piperidine spiro triazine derivative 21 together with thiazole derivative 22 is obtained, the spiro compound 21 being the major reaction product . 

A novel intumescent flame-retardant (IFR) system composed of a phosphorous-nitrogen (PSPTR)-containing spiro triazine structure and phenol formaldehyde resin (PF) was investigated by Hu et al. (Hu et al. 2012). 

Aminomethylation of 2-ami no-5,5-bis(hydroxymcthyl)-l,3-thiazol-4(5//)-onc and its spiro analogs gave the corresponding [l,3]thiazolo[3,2-o][l,3,5]triazine derivatives <06CHE1086>. 

The condensation reaction of the spiro-substituted partially saturated thiazolo[3,2-3][l,2,4]triazine compound 149 was published by Abdel-Rahman et al. <1994PHA729>, as shown in Scheme 22. The transformation was carried out in glacial acetic acid under heating to yield the ethenyl derivative 150 in acceptable yields (55-60%). 

The 1,2,3-triazine ring was constructed from o-aminophenyl oximes in the conditions of nitrosation (NaN02/HCl) , while hydrazinooximes were used for the synthesis of the 1,2,4-triazine ring Thus, cyclization of a-hydrazinooxime 342 with Pb304 in the presence of acetic acid afforded 1,2,4-triazines 343 in 44-54% yields (equation 149) . Interaction of oxime 344 with hydrazine leads to the spiro compound product 345 in 73% yield (equation 150) °. 

When two equivalents of an isocyanate are treated with one equivalent of an enamine, a l,3,5-triazine-2,4-dione is formed. The novel spiro compound (171) may be prepared by this route. The spiro derivative is isomerized on heating (69CB931). 

There are few examples of this type of synthesis. Typically, an azirine reacts with isocyanates or isothiocyanates to yield the triazine via a series of dipolar intermediates. The products may be contaminated with the isocyanate trimer the example of Scheme 114 below is typical. The novel spiro compound (188) is formed by a similar route (Scheme 115) (79HCA1429, 81LA264). 

Tetrahydropyridine 152, handled as triazine 153, in the presence of metal catalysts, undergoes insertion into spiro-fused cyclopropane 156 to give the tetracyclic adduct 157 in an 86 14 mixture of diastereoisomers. 

Substituted 1,2,4-triazines and 1,2,4,5-tetrazines are known to undergo [2-1-4] cycloaddition with inverse electron demand when reacted with alkenes. The primary bicyclic product loses nitrogen to give dihydropyridines and dihydropyridazines, respectively. The reaction of methylenecyclopropane with dimethyl-1,2,4,5-tetrazine-3,6-dicarboxylate at room temperature gave the spiro-dihydropyridazine 2 in 80% yield. ... 

When bicyclopropylidene was treated in the same way only trimers of the initially formed 8,9-diazadispiro[2.0.2.4]deca-7,9-diene were isolated.The cycloaddition reaction of the unsym-metrical dimethyl 3-cyano-l, 2,4-triazine-5,6-dicarboxylate with methylenecyclopropane was re-gioselective. The primary product was the 2-cyanospiro-3,4-dihydropyridine system (with C3 as spirocenter) which hydrolyzed readily upon chromatography. Dimethyl 4-oxo-5-aza-spiro[2.5]oct-5-ene-6,7-dicarboxylate was isolated as a stable product in 8%> yield. ... 

Reaction of 4,5,6-tris(perfluoroalkyl)-l,2,3-triazines 1 with alkenes or dienes starts with an attack at N2 and leads to the isolation of 2-alkyl-2,5-dihydro-1,2,3-triazines 2 and 3 or the spiro compounds 4.2hS 267... 

Spirocyclic triazolines are rare entities, however reduction of a-azidocycloalkyl-nitriles (or amides) affords spirocyclic triazolines in variable amounts. Azide (85a) afforded cyanoamine (86a) and spiro-l,2,3-triazole (87) in 56% and 16% yield, respectively. Similarly, azide (85b) afforded the spiro-l,2,3-triazolone (88) in 25% yield along with some starting material, some reduced linear triazine and the amine (86b). When 88 was thermolyzed in acetic acid, the a-acetoxyamide (89) was obtained [94JOC(59)6853]. 

Nitrogen, Sulphur and Selenium-containing Compounds. - The S- and 6-substituted 3-amino-l,2,4-triazines 5 and 6, the spiro-naphthoxazine 7, the hetero Diels-Alder cycloadduct 8, 5-azido-3-0-benzyl-6-0-tert-butyldiphenylsilyl-5-deoxy-1,2-O-isopropylidene-P-L-talofuranose, 9 5-azido-6-0-benzoyl-3,5-dideoxy-3-fluoro-l,2-<9-isopropylidine-a-D-glucofuranose, kedarosamine (2,4-dideoxy-4-dimethylamino-L-fucopyranose) as the 3-0-(4-bromobenzoyl) derivative. 1,2 5,6-Di-0-isopropylidene-a-D-ribohexos-3-ulose phenylhydrazone, p-iactam 9 (from a diastereoselective [2+2] cycloaddition to a carbohydrate-based arylimine), 3 the D-arabino and D-ribo lactam derivatives 10 and 11, " the fully-protected iminosugar 12, 5 2,3,4,5-tetra-0-acetyl-6-amino-6-deoxy-D-mannonolactam, 4,8-anhydro-3-... 

A (1/7-imidazol-l-yl) silver species (55) has been postulated as the key intermediate in the 3-l-2-cycloaddition reaction of diazoalkanes (54) with benzynes yielding 2-aryl-2H-indazoles (56) (Scheme 18). The 3-I-2-cycloaddition reaction of 3-trifluoromethyl-4-diazopyrazolinones with dialkyl acetylene dicarboxylates, in refluxing toluene, produced spiro 3/f-pyrazole adducts that rearranged to the trifluoromethyl-substituted pyrazolo[l,5-fi(][l,2,4]triazin-7-ones. ° The 1,3-dipolar cycloaddition reaction of aromatic thioketones (58) with 2-aza-1,3-dicarbonyl compounds (57), at 20-50 C, yielded thiadiazoline adducts (59) that readily eliminate nitrogen to produce oxathioles (60) in moderate yields (up to 70%) (Scheme 19). ... 

Figure 7.4 shows the structures of typical electron transport organic semiconductors. Alq3, which can act both as an electron conductor and green emitter, was used by Tang in his first OLEDs and is still in use today. Besides metal complexes electron deficient heterocycles are frequently used as electron transport materials. The triazine derivative TPT [14, 15], the oxadiazole PBD and its spiro analogue spiro-PBD [16, 17] and the benzimidazole TPBI serve as typical examples. 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) has a very low HOMO level and is often used as a hole blocking layer. 

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