COc1cccc(-c2ccc(NC(=O)C3CCCN(Cc4cnc(N(C)C)s4)C3)cc2)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?