COc1ccc(/C=C2\SC(=O)N(CC(=O)NN3CCN(C)CC3)C2=O)cc1OC
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?