COCCn1c(N)c(C(=O)Nc2sc3c(c2C(=O)OC)CCCC3)c2nc3ccccc3nc21
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?