CC1CCCCN1Cc1c(O)ccc2c(O)c(-c3nc4ccccc4s3)c(=N)oc12
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?