1707-15-9 4-Pyridinecarboxylic acid, 2,2'-methylenedihydrazide Bis(isonicotinylhydrazo)methane Isonicotinic acid 2,2'-methylenedihydrazide Isonicotinic acid, 2,2'-methylenedihydrazide Metazid Metazide Methazid Methazide N,N-Methylenebisisoniazid NSC39302 Ro 2-4969 Ro 24969