Clonazolam is in the benzodiazepine class. Benzodiazepines contain a benzene ring fused to a diazepine ring, which is a seven membered ring that has the two nitrogen constituents located at R1 and R4. The benzyl ring of clonazolam, is substituted at R8 with a nitro group NO2-. The diazepine ring is also bonded at R6, to a 2-chlorinated phenyl ring.
Clonazolam contains a 1-methylated triazole ring fused to, and incorporating R1 and R2 of its diazepine ring. Clonazolam belongs to a class of benzodiazepines containing this fused triazole ring, called triazolobenzodiazepines, distinguished by the suffix -zolam. Other nitrobenzodiazepines include clonazepam and flunitrazepam.