CCOC(=O)c1c(N2CCOCC2)[nH]c(=O)c(C(c2cccs2)c2c(O)c(C(=O)OCC)c(N3CCOCC3)[nH]c2=O)c1O
A lower number of negative pKa indicates that the acid dissociates more entirely in water. What is the negative pKa of this molecule?