1.3.5- Triazine-2 -thiones 3.4- dihydro- from

Synthesis of 4(6)-amino-l,3,5-triazine-2-ones and 2-thiones starting from benzotriazole derivatives has been reported <01JOC6797>. The first template photochemical synthesis of a 1,3,5-triazine derivative as a receptor capable of differentiating between thymine and uracil has been described <01CC1446>. A new solid phase synthesis of trisubslituted 6-amino(substituted)-2,4-dioxo-3,4-dihydro-l,3,5-triazines from a resin-bound amine component has been reported <01JCO278>. The synthesis of thirteen lris(azol-l-yl)-13,5-triazines, as a new class of multidentatc ligands, has been described <01H(55)905>. Tris(pyrazolyl-13,5-triazincs) 14 have been prepared by cyclotrimerization of aromatic nitriles, in piperidine and in solvent-free conditions <01T4397>. 

Reaction of 5,6-diphenyl-1,2,4-triazin-3-one (215) or 5,6-diphenyl-l,2,4-triazine-3-thione (216) with benzene under Friedel-Crafts conditions led to the isolation of 5,5,6-triphenyl-4,5-dihydro-l,2,4-triazin-3-one (217) and -3-thione (218) respectively (76IJC(B)273). Reacting under similar conditions (C6H6/A1C13) the 6-styryl compounds (219-221) are converted into the corresponding 6-(2,2-diphenylethyl) derivatives, e.g. (222) from (219) (75IJC1098). 

Re multiple bond character. This result raises the important question as to whether some of the rhenium(IV) complexes that are believed to contain a linear Re—O—Re unit (Section 43.6.1.7) might not in reality have structures related to this oxalate derivative. The suggestion that the Re,v complex with 5,6-diphenyl-2,3-dihydro(asym)triazine-3-thione (HL), that has been used for the spectrophotometric determination of rhenium, might be Re2(ju-0)2L4, containing bidentate (N and S) coordination from L, is not without precedent. This complex is prepared by the usual SnCl2 reduction of [Re04] in HC1 in the presence of HL.306... 

Indol-3-yl)-2,3-dihydro-l,2,4-triazine-3-thione was prepared, its X-ray structure determined, and used for the preparation of fused triazolo- and tetrazolotriazines <05RJO875>. Silyl substituted l,2,4-triazin-5-ones have been obtained from a-silyl-a-keto esters and thiosemicarbazide <05TL4049>. 

From the reaction of 6-p-chlorostyryl-3-thioxo-3,4-dihydro-l,2,4-triazin-5(2F/)-one (271) with phenylmagnesium bromide a mixture of seven products was isolated. These were separated and identified as 6-/ -chlorostyryl-5-phenyl-l,2,4-triazine-3(2/f)-thione (272), 6-p-chlorostyryl-5,5-diphenyl-4,5-dihydro-l,2,4-triazine-3(2//)-thione (273), the open-chain compounds (274)- 276), thiosemicarbazide and sulfur (Scheme 49). Mechanisms for the formation of these products were suggested <84JHC905>... 

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