Cationic Charge in the Diazo Component

Diazo components may contain the cationic charge at amino, dialkylamino, trialkylammonium, or cycloammonium groups. 

Diazo Components With Amino alkyl Groups. Yellow dyes are prepared by ami-nomethylation of 2-(4 -aminophenyl)-5-methylbenzothiazole followed by diazoti-zation and coupling with acetoacetarylides. Red cationic dyes are obtained with naphthols or hydroxynaphthoic acid arylides. All are suitable for dyeing paper. The bleachability of these dyes is important for the recycling of waste paper [84], The aminomethylation of aromatic amines is carried out by reaction with formal- 

Yellow paper dyes (e g., 30) are obtained by diazotization of these aromatic amines and coupling with acetoacetarylides [86], 

By coupling to derivatives of I acid, substantive dyes (e.g., 31) are obtained in which the charge on the sulfonic acid group is more than compensated for by the multiple cationic charges. These dye paper in shades of red [87], 

Dyes in which the dialkylaminoalkyl group is connected to the diazo component via a carboxamide [88] or a sulfonamide [89] residue have also been described. 

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