CAS 696-23-1 appears in our catalog under these names: Metronidazole Impurity 1（Metronidazole EP Impurity A）, 2-Methyl-4(5)-nitroimidazole, 99% . Offered by: Hubei YoungXin, Thermo Scientific (Alfa Aesar). Available pack sizes: 10mg, 25mg, 50mg, 100mg, 200mg, 50g, 250g.