Synthesis 2-chlorobenzonitrile is reacted with the Grignard reagent cyclopentylmagnesium bromide to give (2-chlorophenyl)(cyclopentyl)methanone. This is then brominated using bromine to form the corresponding bromoketone, which is then reacted with methylamine in an aqueous solution to form the methylimino derivative, 1-(2-Chloro-N-methylbenzimidoyl)cyclopentanol, with hydrolysis of the tertiary bromine atom. This final intermediate is then heated in decalin or another suitable high-boiling solvent, upon which a ring-expansion rearrangement occurs, forming<unk> . Preparation of<unk> . Structure In chemical structure,<unk>  is an arylcyclohexylamine derivative.<unk>  is a chiral compound. The more active enantiomer, esketamine (S-ketamine), is also available for medical use under the brand name<unk> anest S, while the less active enantiomer, arketamine (R-ketamine), has never been marketed as an enantiopure drug for clinical use. While S-ketamine is more effective as an analgesic and anesthetic through NMDA receptor antagonism, R-ketamine produces longer-lasting effects as an antidepressant. The optical rotation of a given enantiomer of<unk>  can vary between its salts and free base form. The free base form of (S)‑ketamine exhibits dextrorotation and is therefore labelled (S)‑(+)‑ketamine. However, its hydrochloride salt shows levorotation and is thus labelled (S)‑(−)‑ketamine hydrochloride. Detection<unk>  may be quantitated in blood or plasma to confirm a diagnosis of poisoning in hospitalized patients, provide evidence in an impaired driving arrest, or to assist in a medicolegal death investigation. Blood or plasma<unk>  concentrations are usually in a range of 0.5–5.0 mg/L in persons receiving the drug therapeutically (during general anesthesia), 1–2 mg/L in those arrested for impaired driving and 3–20 mg/L in victims of acute fatal overdosage. Urine is often the preferred specimen for routine drug use monitoring purposes. The presence of norketamine, a pharmacologically active metabolite, is useful for confirmation of<unk>  ingestion.
Ketamine
Propofol
Remifentanil
Alfentanil
Fentanyl
Etomidate
Esketamine
Sevoflurane