CCOc1ccc2nc(N3CCCN(C(=O)Nc4ccccc4C)CC3)c(C#N)cc2c1
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?