COc1ccc(CCNC(=O)c2cc(-c3ccc(C)cc3)nc3n[nH]c(-c4ccccc4)c23)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?