COC(=O)/C=C1/N=C(Nc2nc(C)cc(C)n2)N(c2ccc(C)c(C)c2)C1=O
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?