COc1ccc(NC(=O)CC(=O)N/N=C/c2ccc(N(CCC#N)S(C)(=O)=O)cc2)cc1
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?