CCn1cc(/C=C(\NC(=O)c2ccccc2Cl)C(=O)N2CCN(C)CC2)c2ccccc21
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?