White organic solid that forms CO2 with NaHCO3, forms a diazo dye withe beta-naphthol, and reacts with bromine water

A white crystalline solid "X" gives the following chemical tests:


1. It liberates $\ce{CO2}$ with $\ce{NaHCO3}$
2. It forms a coloured dye in diazotisation and coupling with $\beta$-naphthol
3. With $\ce{Br2}$/$\ce{H2O}$, it forms a white precipitate of 2,4,6-tribomoaniline.


"X" can be identified as: 


[![Showing the four answer choices for the above question: (a) 3-aminobenzenesulfonic acid, (b) 4-aminobenzenesulfonic acid, (c) 4-acetamidobenzoic acid, and (d) 3-aminobenzoic acid.](https://i.stack.imgur.com/UOdPc.png)](https://i.stack.imgur.com/UOdPc.png)


I thought that (d) could be the answer as COOH releases $\ce{CO2}$ from $\ce{NaHCO3}$, but can sulphonyl group release $\ce{CO2}$ from $\ce{NaHCO3}$?




(i) indicates presence of 'strong' acidic group: -(SO3H) and -(CO2H) since both are strongly acidic to protonate NaHCO3 and yield CO2.


(ii) indicates presence of Primary Amine which can fully undergo diazotization reaction and then with beta-naphthol form azo dye (coloured dye).


(iii) excess of bromine water forming s-tribromoaniline directly indicates that **Option 2(b) is correct**.


An article on point (iii): [journal\_iisc](http://journal.iisc.ernet.in/index.php/iisc/article/download/1573/4712)


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