Cc1ccc(NC(=O)COC(=O)C2=NN(c3ccccc3)C(=O)CC2)c(Br)c1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?