2-Cl-HHC (2-chloro-hexahydrocannabinol) is a chlorinated derivative of hexahydrocannabinol which has been sold as a designer drug, and is presumed to have cannabinoid activity. It was first identified as a component of a cannabinoid e-cigarette liquid in Japan in 2025 which was represented as being free from illicit cannabinoids such as THC. The active ingredient instead was identified as a mixture of 2-Cl-HHC and 4-Cl-HHC along with 2,4-dichloro-HHC and trace amounts of other chlorinated phytocannabinoid derivatives, as well as the ester Δ9-THCB-O-butanoate. While chlorinated derivatives of THC such as 9-Cl-HHC had previously been identified, their biological activity has not been studied. 2-Cl-HHC has since been added to the controlled drugs list in Hungary.
See also 1'-Dimethyl-Δ9-THCH 2-Allyl-Δ8-THC-O-acetate 4'-Fluorocannabidiol Adamantyl-HHC THC butanenitrile oxime
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