CCNc1nc2nc(O)c3c(c2s1)OC(N)=C(C#N)C3c1ccc(C)cc1
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?