Etoacetazene (Etonitazene 5-acetyl analogue, 5-acetyldesnitroetonitazene) is a benzimidazole derivative with opioid effects, first developed in the 1950s as part of the research that led to better-known compounds such as etonitazene. It is an analogue of etonitazene where the 5-nitro (NO<sub>2</sub>) group has been replaced by an acetyl (COCH<sub>3</sub>) group. It is described as having "reduced but still significant" potency compared to etonitazene itself. This compound was also tested as part of a series of cannabinoid receptor 2 agonists, and was found to be active though with fairly low potency of 960 nM at CB<sub>2</sub>, and negligible activity at CB<sub>1</sub>.