Pyrazolone 5- amino-4-nitro

A similar argument can be applied to the results of later work by Idelson et al.i9 In this they prepared the chromium complex (133) by interaction of the 1 1 chromium complex of 1-phenyl-3-methyl-4-(2-hydroxy-4-cyanonaphth-l-ylazo)-5-pyrazolone and diethylenetriamine and by reaction of the azo compound with [Cr(CO)3dien]. Identical products were obtained and, since the diethylenetriamine occupies9 a facial position in [Cr(CO)3dien], it was concluded that the complex (133) had a facial configuration. Similarly, the reported77 separation of isomeric 2 1 chromium complexes of 2-amino-6-(2-hydroxy-6-nitro-4-sulfonaphth-l-ylazo)-5-naphthol-7-sulfonic acid is... 

In the stepwise synthesis of the unsymmetrical complex dye 13 [ 70236-60-1] [10], the azo dye made from diazotized l-amino-2-hydroxy-5-nitrobenzene and 1-phenyl-3-methyl-5-pyrazolone and the 1 1 chromium complex obtained from 6-nitro-l-diazo-2-hydroxynaphthalene-4-sulfonic acid and 2-naphthol are heated together at 80 °C for 5 h. The adduct is salted out with NaCl. A black powder is obtained that dyes wool and leather in dark brown shades. The resulting colors are fast, particularly on shrink-resistant wool. 

This reaction was extended to other (i-dicarbonyl compounds containing a nitro group [474 176], The mechanism of the reaction of hydrazine with 1,3-dicarbonyl compounds is still largely unclear. Nevertheless, important evidence was obtained to indicate that a dihydroxypyrazolidine intermediate is formed in this reaction [477], If hydroxylamine is used instead of free hydrazine in the reaction with nitromalonaldehyde, the product is 4-nitroisoxazole [471], When a mixture of nitrocyanoacetic ester with one equivalent of hydrazine hydrate and a small amount of water is boiled, 5-amino-4-nitro-3-pyrazolone is formed [478],... 

In mordant dyes, phenols, naphthols, and enolizable carbonyl compounds, such as pyrazolones, are generally the couplers. As a rule, 2 1 metal complexes are formed in the afterchroming process. A typical example of a mordant dye is Eriochrome Black T (18b) which is made from the important dyestuff intermediate nitro-l,2,4-acid, 4-amino-3-hydroxy-7-nitro-l-naphthalenesulfonic acid [6259-63-8]. Eriochrome Red B [3618-63-1] (49) (Cl Mordant Red 7 Cl 18760) (1,2,4-acid — l-phenyl-3-methyl-5-pyrazolone) is another example. The equilibrium of the two tautomeric forms depends on the nature of the solvent. 

CuH NjO, Hipputyl-glycin-azid 3, 240.1110. [x-Nitro-toIuol]-<2 azo 4)-[3-methyl-,pyrazolon-(5)] 84 1316. r2(oder 3)-3ritro-toluol]-<4 azo 4>-[8jmethyl-pyrazdU)n-(6)l 84 1317. 6-Amino-5-[iUTphenyl-nreiao]-2.4-dio -. pyrtmidin 86 II388... 

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