O=C(N[C@@H](Cc1ccccc1)C(=O)OCc1ccccc1)c1nc[nH]c1C(=O)N[C@@H](Cc1ccccc1)C(=O)OCc1ccccc1
A lower number of negative pKa indicates that the acid dissociates more entirely in water. What is the negative pKa of this molecule?