1,2-Propanediamine, N2,N2-dimethyl- 1-Amino-2-(dimethylamino)propane 19764-58-0 63787-54-2 EINECS 243-280-1 N2,N2-Dimethyl-1,2-propanediamine N2,N2-Dimethylpropane-1,2-diamine NSC 166331