TABLE 1.

Molecular structures of benzimidazole opioids (nitazenes).

Nitazene	R1	R2	R3	R4
4-Hydroxy nitazenes	NO2	OH	CH2CH3	CH2CH3
5-Amino Isotonitazene	NH2	OCH(CH3)2	CH2CH3	CH2CH3
Butonitazene	NO2	OCH2CH2CH2CH3	CH2CH3	CH2CH3
Clonitazene	NO2	Cl	CH2CH3	CH2CH3
N-Desethylisonitazene	NO2	OCH(CH3)2	-	CH2CH3
N-Desetyletonitazene	NO2	OCH2CH3	CH2CH3	-
Etodesnitazene	H	OCH2CH3	CH2CH3	CH2CH3
Etomethazene	H	OCH2CH3	CH2CH3	CH2CH3
Etoetonitazene	NO2	OCH2CH2OCH2CH3	CH2CH3	CH2CH3
Etonitazene	NO2	OCH2CH3	CH2CH3	CH2CH3
Etonitazepipne	NO2	OCH2CH3	-CH2CH2CH2CH2-
Etonitazepyne	NO2	OCH2CH3	-CH2CH2CH2CH2-
Flunitazene	NO2	F	CH2CH3	CH2CH3
Isotodesnitazene	H	OCH(CH3)2	CH2CH3	CH2CH3
Isotonitazene	NO2	OCH(CH3)2	CH2CH3	CH2CH3
Methylthionitazene	NO2	SCH3	CH2CH3	CH2CH3
Metodesnitazene	H	OCH3	CH2CH3	CH2CH3
Metonitazene or α-Methylmetonitazene	NO2	OCH3	CH2CH3	CH2CH3
N-piperidino etonitazene	NO2	OCH2CH3	--CH2CH2CH2CH2-
Propylnitazene	NO2	CH2CH2CH3	CH2CH3	CH2CH3
Protonitazene	NO2	OCH2CH2CH3	CH2CH3	CH2CH3