COc1ccc(CN2CCc3nc(SCC(=O)Nc4cc(C)cc(C)c4)[nH]c(=O)c3C2)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?