3-Pyrazolidinone hydrochloride1752-88-130 % similar 2-Methylpyrrolidine hydrochloride54677-53-130 % similar 2,2-Dimethylpyrrolidine hydrochloride623580-01-830 % similar Triethylenetetramine dihydrochloride38260-01-430 % similar Cuprior4961-40-430 % similar