CCN(CC)CCn1c(=S)[nH]c2cc(C(=O)NCc3ccccc3)ccc2c1=O
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?