[MagnificentElectrophile]

Hello, I'm looking for a reaction of converting dicyanide into cyclic imide. I've found a patent article (JP2008106195A) which describes the procedure as below
1,4-diamino-2,3-dicyanoanthraquinone (2.30 g, 8.0 mmol) was added to sulfuric acid (11.7 g) at 80°C. The mixture was stirred at 140-150°C for 1 hour and then cooled to 40°C. Ice water was gradually added and the mixture was cooled to room temperature. After neutralization with sodium carbonate, the precipitate was filtered and washed with water and acetone to give the desired compound (2.37 g, 96% yield).
I believe it involves hydrolysis and condensation and two questions have come up.
1. How could hydrolysis of -CN happen in sulfuric acid at 150°C? Apparently 2 equivalent of water is consumed overall but there isn't that much water in sulfuric acid, which I suppose to be 98% concentrated one.
2. To get the desired compound, hydrolysis-2A needs to selectively happen, not hydrolysis-2B, but how?
I'm really buffled and there are multiple literature where this reaction is mentioned.
Any suggestion would be appreciated.

[rolnor]

98% sulfuric acid contains plenty of water stoichiometrically, water has very low mol mass. It's not 100% sure how this reaction happens, what intermediates are in play

[MagnificentElectrophile]

Thanks for reply, rolnor,

98% sulfuric acid contains plenty of water stoichiometrically, water has very low mol mass.

11.7g sulfuric acid(98%) should only contain 13 mmol (1.63 eq.) water. It doesn't seem sufficient for hydrolysis. But idk. The idea of hydrolysis in heated sulfuric acid itself feels really off to me yet I haven't come up with any alternative. For context, I've tried this reaction once but HNMR spectra was a bloody mess and HPLC-MS didn't look good either. I have no clue what has gone wrong with the procedure itself being so simple.

[rolnor]

Have you followed the procedure exactly? Do you have exactly the same starting material?