COc1ccccc1Cn1c(=S)[nH]c2cc(C(=O)NCc3cccnc3)ccc2c1=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?