Did you take the UV of your amino phenol azo dyes ?

If you use amino phenol azo dyes as SMs, it should have YV peak higher than 280nm.

Can you show the raction? SMs to product you desired?

Did you use NaNO2 to do diazolization of your H2N- on aromatic ring first?

Your question is too vague and must be reformulated. Why?

As :

• Currently doing phd, M.Sc. and M.Phil. Chemistry, you have certainly learned to write a correct description of your reaction!!
• Experimental materials:
• you must write (for the answerers) ..the chemicals and solvents used in this work were of Analar grade p.e. ... .
• According to the answer of Guobing, please take an UV-Vis spectrum of reactant 1 (2-Aminobenzothiazole) and reactant 2 ( your amino phenol azo dye (s). Please give the correct formula of it e.g. them.
• Join the 2 spectra when you will post the new reformulated question.
• when you write :
• I prepared aminobenzothiazole reacted with amino phenol azo dyes , you mean: I prepared the diazonium salt of 2-Aminobenzothiazole as follows:
• Here describe your method of diazotization (acid, sodium nitrite, water, temperature (important) ) .
• Describe the conditions of coupling with reactant 2 (correct formula).
• Describe the protocol of purification after coupling of the obtained dye(s).
• Please give the name of your spectrometer and the kind of cuvettes (Quartz, plastic e.g. PST) . E Value must be between 0-1 and consider the cutoff of the solvent and cuvettes.
• Please note that the answerer (s) is (are) NOT your SUPERVISOR!!
• Submit your question to your supervisor prior you will post it on Research Gate.
• Thank you in advance.
• JRG

280 nm is bi to bi transition of benzene ring

The second transition of n to bi star may be overlapping with the first band our your reaction not occur