COc1cccc(-c2ocnc2C(=O)Nc2ccc(N3CCOCC3)cc2N2CCOCC2)c1
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?