CCOC(=O)c1c(N2CCCC2)[nH]c(=O)c(C(c2ccc(Cl)c([N+](=O)[O-])c2)c2c(O)c(C(=O)OCC)c(N3CCCC3)[nH]c2=O)c1O
A lower number of pka indicates that the acid dissociates more entirely in water. What is pka of the molecule?