has role has functional parent cyclohexanones analgesic xenobiotic intravenous anaesthetic neurotoxin secondary amino compound NMDA receptor antagonist ketamine A member of the class of cyclohexanones in which one of the hydrogens at position 2 is substituted by a 2-chlorophenyl group, while the other is substituted by a methylamino group. environmental contaminant monochlorobenzenes norketamine