^abNichols DE (2018).Chemistry and Structure-Activity Relationships of Psychedelics. Current Topics in Behavioral Neurosciences. Vol. 36. pp. 1–43.doi:10.1007/7854_2017_475.ISBN978-3-662-55878-2.PMID28401524.One of the earliest modifications of the tryptamines to be studied for psychoactive effects was the N,N-diethyl analogue of psilocin (CZ-74, 16). Both CZ-74 and its O-phosphoryl derivative CEY 19 (17) were studied in humans. Qualitatively, these compounds were very similar to psilocin and psilocybin, respectively, but had somewhat reduced durations of action (Leuner and Baer 1965).
^Shulgin AT (1976). "Psychotomimetic Agents". In Gordon M (ed.).Psychopharmacological Agents: Use, Misuse and Abuse. Medicinal Chemistry: A Series of Monographs. Vol. 4. Academic Press. pp. 59–146.doi:10.1016/b978-0-12-290559-9.50011-9.ISBN978-0-12-290559-9.Although the N-dealkylated homologs are as yet untested clinically, the N,N-diethyl homologs of psilocybin and of psilocin have been studied in man (Leunder and Baer, 1965). These compounds [CEY-19, (XXXIII); CZ-74, (XXXIV)] in dosages of from 5 to 20 mg appear to resemble psilocybin in the qualitative nature of their action but to be of shorter duration. Maximum effects are obtained in an hour, and 2 hours later the subject is for the most part recovered, thus providing a valuable time course for psychiatric therapy.
^abPassie, Torsten (7 November 2022). "History of the Use of Hallucinogens in Psychiatric Treatment". In Grob, Charles S.; Grigsby, Jim (eds.).Handbook of Medical Hallucinogens. Guilford Publications. pp. 95–118.ISBN978-1-4625-5189-7.Psycholytic therapy underwent a number of modifications during its active years. Some European therapists experimented with shorter-acting psilocybin derivatives such as CZ-74 (4-hydroxy-N,N-diethyltryptamine, also known as 4-HO-DET; Baer, 1967; Shulgin & Shulgin, 2014), which has a duration of 4—6 hours and is phenomenologically similar to LSD; CEY-19 (phosphoryloxy-N,N-diethyltryptamine, also known as 4-PO-DET or ethocybin), which has a duration of 2—4 hours and is also similar to LSD, and the mescaline derivative 2-CD (2,5-dimethoxy-4-methylphenethylamine; Schlichting, 1989). Therapists in the United States experimented with the short-acting dipropyltrytamine (DP T) in psycholytic therapy (Soskin, 1975; Soskin, Grof, & Richards, 1973), as well as in psychedelic therapy (Richards, Rhead, DiLeo, Yensen, & Kurland, 1977).
^abRoss S, Franco S, Reiff C, Agin-Liebes G (9 March 2021). "Psilocybin". In Grob CS, Grigsby J (eds.).Handbook of Medical Hallucinogens. Guilford Publications. pp. 181–214.ISBN978-1-4625-4544-5.Sandoz began manufacturing and distributing pure synthetic psilocybin pills (under the name Indocybin) to curious physicians and researchers around the world and would do so until recalling the drug in 1965 due to a growing political backlash in the United States (Hofmann, 2005). Sandoz also produced two synthetic drugs derived from mushroom-extracted psilocybin, CZ-74 (4-hydroxy-N,N-diethyltryptamine) and CEY-19 (4-phosphoryloxy-N,N-diethyltryptamine), both of which are shorter (approximately 3 hours in duration) acting than psilocybin (Baer, 1967). [...]
