5-Phenyl-2-phenylazo

Analog wird 2-Phenyl-2-phenylazo-butan (gelbes 0l) erhalten. 

Pyridinone di-(2-quinolinylmethylene) hydrazone, see D-01102 2(1 f/)-Pyridinone [[(3-methoxyphenyl)azoJ phenylmethylenejhydrazone, P-00359 2(1 //)-Pyridinone [[(4-methoxyphenyl)azoJ phenylmethylenejhydrazone, P-00360 2(1 //)-Pyridinone [[(4-methylphenyl)azoJ phenylmethylenejhydrazone, P-00361 2( 1 //)-Pyridinone [[(3-nitrophenyl)azoJ phenylmethylenejhydrazone, P-00362 2(1 //)-Pyridinone [[(4-nitrophenyl)azoJ phenylmethylenejhydrazone, P-00363 2(1 //)-Pyridinone [phenyl(phenylazo) methylenejhydrazone, P-00364 2( 1 //)-Pyridinone [2-phenyl-1 -(2-pyridinyl) ethylidenejhydrazone, P-00365 2( 1 //)-Pyridinone (1 -pyrazinylethylidene) hydrazone, P-00366... 

Phenyl-2-pyridyl)-5-(2-pyridyl)-1,2,4-triazoline, P-00185 2(l//)-Pyridinone [phenyl(phenylazo) methylene]hydrazone, P-00364 l-(2-Pyridinyl)-3,5-diphenylformazan, P-00387... 

Tri-Me ether, oxime, in T-00273 2(1//)-Pyridinone [phenyl(phenylazo)methylene] hydrazone, P-00364 2(lH)-Pyridinone [[(4-methylphenyl)azo] phenylmethylene]hydrazone, P-00361... 

Acyl-, 4-alkoxycarbonyl- and 4-phenylazo-pyrazolin-5-ones present the possibility of a fourth tautomer with an exocyclic double bond and a chelated structure. The molecular structure of (138) has been determined by X-ray crystallography (Table 5). It was shown that the hydroxy group participates in an intramolecular hydrogen bond with the carbonyl oxygen atom of the ethoxycarbonyl group at position 4 (8OCSCII21). On the other hand, the fourth isomer is the most stable in 4-phenylazopyrazolones (139), a chelated phenyl-hydrazone structure. 

The acetyl transfer reactions of acetylated pyrazolones (acylotropy) have been carefully studied by Arakawa and Miyasaka (74CPB207,74CPB214) (Section 4.04.2.1.3(x)). Methylation of 3-methyl-l-phenyl-4-phenylazo-5-pyrazolone (402) yields, depending on the experimental conditions, the N- and the O-methylated derivatives (483) and (484) (66BSF2990). These derivatives have been used as model compounds in a study of the tautomerism of (402) (structure 139 Section 4.04.1.5.2). 

Pyrazol-5-one, 3-methyl-1 -phenyl-4-phenylazo-methylation, 5, 264 Pyrazol-5-one, pyridyl-biological activity, 5, 295 Pyrazol-5-one, l-(4 -carbamoylphenyl)-3-methyl-azo pigments from, 1, 334 Pyrazol-5-one, 3-methyl-l-phenyl-azo dyes from, 1, 330 azo pigments from, 1, 334 Pyrazolones acetylated acylotropy, 5, 264 analytical applications, 5, 300 anions... 

Pyrimidine, 2,2,4,4,6-pentamethyl-2,3,4,5-tetrahydro-conformation, 3, 62 synthesis, 3, 118 Pyrimidine, perhydro-polymers, 1, 313-314 Pyrimidine, phenyl-nitration, 3, 78 Pyrimidine, 4-phenyl-synthesis, 3, 72, 116 Pyrimidine, 5-phenylazo-synthesis, 3, 131 Pyrimidine, 4-phenyI-6-styryl-1-oxide... 

In the context of their new synthetic route to arenediazo phenyl ethers (see Sec. 6.2), Tezuka et al. (1987 a, 1989) investigated the reaction products of phenyldi-azo 1-naphthyl ether (12.10) under various conditions. When an acetonitrile solution of the diazo ether 12.10 was kept standing at room temperature for one week in the dark, the 4- and 2-phenylazo-l-naphthol isomers (12.11 and 12.12) were formed in 48% (20%) and 9% (8%) yields respectively. In the presence of acid (aqueous HC1 or H2S04) or of various bases (aqueous NaOH, pyridine, aniline, or sodium acetate) the yields of the azo products are much lower, but higher proportions of biphenyl, 1-naphthol, and phenol are formed. The crosscoupling product l-phenylazo-2-naphthol was not detected when the reaction was carried out in the presence of 2-naphthol. As this mechanistic test reaction gave rather low yields of the two azo compounds 12.11 and 12.12 in the presence and absence of 2-naphthol,... 

The H and 13C CIDNP studies have shown that not only the sulfone 14, but also the sulfmic ester 15, is generated as cage products from the phenyl/p-toluenesulfonyl radical pair during the thermal decomposition of phenylazo aryl sulfone (13)54 (Scheme 2). The cross-termination of arenesulfonyl and triethylgermyl radicals was found to occur exclusively via the formation of germyl sulfinate, ArS(0)0GeEt333. 

Alkalimetallhydride reduzieren nicht. Man isoliert ausschlieBlich Olefine22. Bei der Umsetzung von Cyclo-hexanon-N-phenyl-N-tosyl-hydrazon mit Lithiumhydrid erhalt man die Azo-Stufe der Bamford-Stevens-Reaktion unter Bildung von Phenylazo-cyclohexen1. ... 

Pcnten-(2)-yl-(4)- -diathylester 204 Pentyliden-(2)- -dinitril 666 1-Phenyl-athyliden- -dinitril 643 4-Phenylazo-benzoyl- -diathylester 195 (1-Phenyl-propyl)- -dinitril 559 (1-PhenyI-propyliden)- -dinitril 559 PropyI-(2-methyl-aIlyl)- -diathylester 202... 

Oxo-9,10-dihydro- 654 l-Oxo-l,2,3,4-tetrahydro- 765 4-Oxo-l,2,3,4-tetrahydro- 766 9-Phenylazo- 482 9-(2-Phenyl-hydrazino)-... 

Phenoxy-2-quinoxalinecarbonyl chloride 3-Phenoxy-2-quinoxalinecarboxylic acid 3-Phenoxy-2(l//)-quinoxalinone 3-Phenylazo-2(l//)-quinoxalinone 2-Phenyl-3,6-dipiperidino-5,8-quinoxalinequinone... 

Vicente, J., and Chicote, M.T. (1981) Synthesis and reactivity of dichloro 2-(phenylazo)phenyl gold(III). Inorganica Chimica Acta, 54, L259. 

The mesoionic tetrazole dehydrodithizone is transformed by iron penta-carbonyl into 4-phenyl-2-phenylazo-A2-l,3,4-thiadiazolin-5-one, presumably by a mechanism of ring opening, complexation, carbonyl insertion and subsequent ring closure (Scheme 128).193 Unfortunately, analogous processes do not occur on other mesoionic compounds in the 1,2,3-oxadiazole, s-triazole or tetrazole series, and the scope of this unusual carbonylation is probably limited. 

The existence of cage effect was proved in the experiments on photolysis of the optically active azo-compounds. The photodecomposition of these compounds is accompanied by racemization [3], For example, the partial (40%) photolysis of optically active 2-phenylazo-(2-phenyl)-butane in a hexadecane solution provides racemization to 26% [87]. The fraction of geminate recombination was found to be 52% (hexadecane, room temperature) ... 

The procedure given here is essentially that described previously by the submitters2 and is based on the early work of Knoevenagel.8 2-Phenylindazole has been prepared by reduction of N-(o-nitrobenzyl)aniline with tin and hydrochloric acid,4 by reduction of N-(o-nitrobenzyl) -N-nitrosoaniline with tin and hydrochloric acid,5 by dehydration of 2-(phenylazo)benzyl alcohol,6 by elimination of acetic acid from 2-(phenylazo)benzyl acetate,7 by dehydrogenation of 3,3a,4,5,6,7-hexahydro-2-phenyl-indazole with sulfur,8 and by thermal decomposition of o-azido-benzalaniline.9... 

The reaction of 6-methyl-3-phenyl-(l//)pyrazolo[5,l-c][l,2,4]triazole 56 with phenyldiazonium chloride affords 177-6-methyl-3-phenyl-7-phenylazo-pyrazolo[3,2-f][l,2,4]triazole 183 the structure of this compound was unequivocally assigned when compared with an identical product prepared in the reaction of compound 56 with acetic anhydride followed by azo coupling and basic hydrolysis (Scheme 5) <2003RRC533>. 

The solvent effect on the azo-hydrazone equilibrium of 4-phenylazo-l-naphthol has been modelled using ab initio quantum-chemical calculations. The hydrazone form is more stable in water and in methylene chloride, whereas methanol and iso-octane stabilise the azo form, The calculated results were in good agreement with the experimental data in these solvents. Similar studies of l-phenylazo-2-naphthol and 2-phenylazo-l-naphthol provided confirmation. Substituent effects in the phenyl ring were rationalised in terms of the HOMO-LUMO orbital diagrams of both tautomeric forms [53]. 

---