Dear Dr. Mahesh,

                                  The structure of bromaminic acid has both amine group and bromine. However, the amine group in the 2,4,6-trimethyl-3,5-diamino-benzenesulfonic acid will be more reactive for C-N coupling, induced by CuCl. The reason is indirect conjugation of the amine group with sulphonic acid. 

Although the amine group in the bromaminic acid is in the direct conjugation with sulphonic acid, it can still participate in self-coupling among these molecules. The possible solution may be protection of the amino group of bromaminic acid by acetylation or benzoylation. The acid formed in the acetylation or benzoylation reaction should be removed otherwise it will interfere in the CuCl-catalyzed reaction. Once the desired product is obtained, it can be further deacetylated or debezoylated.

a) The reaction is slow to acidic nature of sulfonic acid, make as sodium salt of sulfonic acid then try ulmann reaction maintaining the pH at  8.0 -  9.0.

Chhatbar,

You have nice answers, however \i would like to bring your attention to

--- Synthesis of reactive blue P-3R

Mao, Faming,   Ranliao Yu Ranse, 48(1), 1-2; 2011

Where the reported reaction conditions are

1.1 R:NaOH, S:H2O, 50-55°C, pH 7-8

1.2 R:NaHCO3, R:Disodium carbonate, rt, pH 8.5

1.3 R:CuCl, rt; 1.5 h, rt → 75°C; 20 h, 75°C

Good luck

Dear Mr. KUMAR, and Amer,

Thank you for give me your valuable suggestions and hint on my project.

Mr. Kumar you are right there may be chance to self condensation reaction of B-acid, thats why i am taking extra mole of M-acid so is it preferable?. If i protect the NH2 group by acetylation  two step to be add. Shell we use CuSO4 instead of CuCl?. How much possibility of hydrolyze of B-acid ?.

Thank you

Regards

Dr. Mahesh

Dear Mahesh,

                         CuSO4, however is commercially cheaper,  will not be suitable for the C-N coupling reaction. The catalysts like CuCl, CuBr and CuI can only catalyze the C-N coupling. However, the hydrolysis of the B-Acid should not be very difficult, and can be carried out by proper concentration of base.

Dear Mr. Kumar

Method for synthesizing anthraquinone type dye or chromophore by aromatic amination of bromamine acid

CN 104312193 A

I am following this way route.\

As per your suggestion i will try

Thanks

https://www.google.co.in/patents/CN104312193A?cl=en&dq=2,4,6-trimethyl-3,5-diamino-benzenesulfonic+acid&hl=en&sa=X&ved=0CFgQ6AEwCGoVChMI8b6BgLKPxwIVi8KOCh0d9QUI

The main problem here is that you are working with benzosulfonic acid with 2 amines. This reduces the electronegativity of the 5-amine rather than the 3 amine and hence trying to condense it with Bromamine is giving you the most obvious result..

Dear Dr. Mahesh, 

                                Sometime,  patent reactions are not very fruitful, so try these, by keeping the reactants in the proper mole-ratio.