4-Amino-3-phenylazo

Das bei der Umsetzung von 3,4-Diamino-furazan mit Nitroso-benzol erhaltene 4-Amino-3-phenylazo-furazan (I 27%) liefert mit Blei(IV)-acetat 5-Phenyl-(1,2,3-azeniaazoniaazolo 4,5-c]-furazan) (II 28%)257 258, das auch aus 4-Amino-3-azido-furazan mit Nitroso-benzol zugang-lich ist259 ... 

Phenyl-(1,2,3-azeniaazoniaazolo[4,5-c]furazan y (II) 1,1 g (5,8 mmol) 4-Amino-3-phenylazo-furazan werden mit 3,5 g Blei(IV)-acetat in 50 ml Benzol 23 h unter Riickfl. erwarmt. Nach Filtration wird das Lo-sungsmittel abgedampft und der Riickstand mit Benzol an Kieselgel (Wakogel C-200) chromatographiert Ausbeute 0,3 g (28%) Schmp. 165,5-166,5" (Benzol und Ethanol/Aktivkohle). 

Bis-[4-amino-phenylazo]-azobenzol erhalt man in Dimethylacetamid bei 20° in 75% Ausbeute6. 

Amino-phenylazo)-8-hydroxy quinoline styrene acryloyl chloride copolymer ethylene glycol DMF... 

The Chemicaly3.bstractIndexis 2,7-naphthalene-disulfonic acid, 4-amino-5-hydroxy-3-[[4 -[(4-hydroxyphenyl)azo] [l,l -biphenyl]-4-yl]azo]-6-(phenylazo)-, disodium salt. 

The reaction of 6-amino-5-(l,2-diethoxycarbonylhydrazino)pyrimidines with enamines represents another convenient method for the preparation of pteridines. Fusion of 5-(l,2-diethoxycarbonylhydrazino)-2,4,6-triaminopyrimidine (281) with an excess of mor-pholinocyclohexene leads to 2,4-diaminotetrahydrobenzo[g]pteridine, and with the morpholinoenamine (282) from 17/3-hydroxy-5a-androstan-3-one regioselective condensation to the fused pteridine (283) takes place in almost quantitative yield (equation 101) (71CC83). 6-Amino-5-nitroso- and 6-amino-5-phenylazo-pyrimidines react similarly, imitating the Timmis-type reaction (72CPB1428). 

A totally different picture is presented by 3-phenylazo-2-naphthol. This unusual isomer cannot be prepared by a normal coupling procedure but has been obtained by reaction of 3-amino-2-naphthol with thionyl chloride to give the N-sulphinylamine (4-24), condensation of which with N-phenylhydroxylamine yields the desired product [59]. Here, assumption of a ketohydrazone form would entail loss of aromatic character in both rings of the naphthalene nucleus and the energetic unfavourability of this situation ensures that the compound exists solely in the hydroxyazo form. 

Amidoblack 4-Amino-5-hydroxy-3-[4-nitrophenyl)azo]-6-(phenylazo)-2,7-naphtalenedisulphonic acid disodium salt... 

Sulfasalazine Sulfasalazine, 5-[p-[(4,6-dimethyl-2-pyridinyl)sulfamoyl]phenylazo]sali-cylic acid (33.1.22), is a derivative of sulfapyridine drug described above and one of the few sulfanilamides in which the free amino group in the benzene ring is modified, and it is synthesized by an azo-coupling reaction of a diazo salt, which is synthesized by reacting sulfapyridine (33.1.21) with nitrous acid and salicylic acid alkaline media [24,25]. 

Das ebenfalls aus 4-Amino-3-azido-furazan mit Anilin bei 150° zugangliche 4-Amino-3-phe-nylazo-furazan reagiert mit Nitrosyl-Verbindungen bei anschlieBender Behandlung mit Azid-Ionen zu 4-Azido-3-phenylazo-furazan. Letzteres liefert in der Warme ebenfalls das Betain I259 ... 

Sowohl bei der Umsetzung von 4-Amino-3-azido-furazan mit Nitrosobenzol als auch durch Erwarmen von 4-Azido-3-phenylazo-furazan wird 5-Phenyl-(1,2J-azeniaazoniaazolo[4,5-c fu-razan) er nalten259 ... 

J 8- (4-Jod-phenylazo) -5-( 3-piperidino-propyl-amino)-tetralin 49 188-190 antibiotisch 1... 

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