4.6- dimethyl-l,2,3-triazine

Diaz-Ortiz described the cycloaddition of 4,6-dimethyl-l,2,3-triazine (105) with en-amines to give condensed pyridine systems [82]. These reactions were performed in a monomode reactor at a power of 270 W for 20 min at 15 °C. The reactions can also be performed with pyrrolidine, with cyclic ketones used as precursors of the enam-... 

X-ray crystallographic analysis of 6-methyl-4-phenyl-l,2,3-triazine 1-oxide (8),22 1-methyl-4,6-diphenyl-l,2,3-triazinium iodide (9),23 4,6-dimethyl-l,2,3-triazine 2-oxide (10a),19 4,6-diphenyl-1,2,3-triazine 2-oxide (10b),19 4,5,6-triphenyl-l,2,3-triazine 2-oxide (10c),36 4,5,6-tris(4-tolyl)-... 

Ruthenium porphyrin did not catalyze the oxygen transfer from 4,6-dimethyl-1,2,3-triazine 2-oxide to alkenes, alcohols or sulfides 4,6-dimethyl-l,2,3-triazine was not detected.261... 

Heating 4,6-dimethyl-l,2,3-triazine (1, R1 = R3 = Me R2 = H) with 1,1-diethoxyethene in a sealed tube to 180°C afforded two isomeric pyridines 4 and 5 the formation of the products has been explained by intermediate formation of 2,4-dimethylazete (3).285... 

The bond energy E y and the bond length r are related by E y= 1/r thus, there should be a correlation between aromaticity indexes and resonance energies. Accordingly, a unified aromaticity index 7a has been defined (reference benzene 7a=100), and 7a=77 for 1, 86 for 1,2,4- and 100 for 1,3,5-triazine <1992T335>. From molecular dimensions, 7a = 77 has also been calculated for both 4,6-dimethyl- and 4-methyl-6-phenyl-l,2,3-triazine, 73.4 for 4,6-dimethyl-l,2,3-triazine 2-oxide, 76.0 for 4-methyl-6-phenyl-l,2,3-triazine 2-oxide, and 68.95 for 6-methyl-4-phenyl-1,2,3-triazine 1-oxide <1993T8441>. In this sense, N-oxidation is accompanied by a reduction in aromatic character. 

While the parent 1,2,3-triazine 1 is reported not to react with OT-chloroperbenzoic acid (MCPBA) even after 3 days <1992H(33)631>, 4-methyl-1,2,3-triazine 86c, 4,6-dimethyl-l,2,3-triazine 17m, and 4-methyl-6-phenyl-l,2,3-tri-azine 17s gave mixtures of 1-oxides (minor) and 2-oxides (major) when treated with MCPBA or ACOH/H2O2. In contrast, 4,5,6-triphenyl- and 4,6-diphenyl-l,2,3-triazine gave solely the 2-oxides <1996CHEC-II(6)483>. 

Reaction of preformed enamines (or cyclic ketones and pyrrolidine) with 4,6-dimethyl-l,2,3-triazine 17m in a focused microwave reactor (atmospheric pressure, 270 W, 20 min, max. temp. 150 °C) allowed the preparation of various annelated pyridines with considerably improved yields <2001SL236> compared to the conventional thermal method (200-220°C in 1,2-dichlorobenzene) <1989H(29)1809>. 

A thermal reaction of the strained diene fullerene C6o with 4,6-dimethyl-l,2,3-triazine 17m gave the azacyclohexadiene-fused fullerene derivative 146 and another product 147a after separation of the product mixture by silica gel flash chromatography. Compound 147a has an eight-membered orifice of the C6o cage (Scheme 10)... 

The deoxygenation of 1,2,3-triazine 1- and 2-oxides by catalytic hydrogenation to give 2,5-dihydro-l,2,3-triazines has been reviewed in Section 9.01.5.6 (Equation 46). 4,5,6-Triaryl-l,2,3-triazine 2-oxides are transformed into the corresponding 1,2,3-triazines by treatment with triethyl phosphite <1985LA1732>. In contrast to other heteroaromatic A -oxides, 4,6-dimethyl-l,2,3-triazine 2-oxide does not transfer its oxygen to alkenes under catalysis by [dioxo(tetramesitylporphyrinato)mthenium(vi)] <1991TL7435>. 

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