Structural formula
Space-filling model of methylpentynol
Clinical data
Trade namesOblivon
Routes of
By mouth
ATC code
Legal status
Legal status
  • BR: Class C1 (Other controlled substances)[1]
  • Withdrawn
  • 3-methylpent-1-yn-3-ol
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard100.000.960 Edit this at Wikidata
Chemical and physical data
Molar mass98.145 g·mol−1
3D model (JSmol)
  • CCC(C)(C#C)O
  • InChI=1S/C6H10O/c1-4-6(3,7)5-2/h1,7H,5H2,2-3H3 ☒N
 ☒NcheckY (what is this?)  (verify)

Methylpentynol (Methylparafynol, Dormison, Atemorin, Oblivon) is a tertiary pentynol with hypnotic/sedative and anticonvulsant effects and an exceptionally low therapeutic index. It was discovered by Bayer in 1913[2] and was used shortly thereafter for the treatment of insomnia, but its use was quickly phased out in response to newer drugs with far more favorable safety profiles.[3][4][5]

The drug was marketed again in the United States, Europe and elsewhere from 1956 well into the 1960s as a rapid-acting sedative.[6] The drug was quickly overshadowed at that point by benzodiazepines and is no longer sold anywhere.[7]


Methylpentynol is prepared by reaction of butanone (MEK) with sodium acetylide in liquid ammonia. This reaction must be done in anhydrous conditions and in an inert atmosphere.


As building block in the synthesis of:

  1. Phthalofyne (1,2-Benzenedicarboxylic acid, mono(1-ethyl-1-methyl-2-propynyl) ester) [131-67-9]
  2. Anansiol (1-ethyl-1-methylprop-2-ynyl carbamate) [302-66-9]
  3. Bason ( 2-Bromoethynyl-2-butanol) [2028-52-6]

See also


  1. ^ Anvisa (2023-03-31). "RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial" [Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control] (in Brazilian Portuguese). Diário Oficial da União (published 2023-04-04). Archived from the original on 2023-08-03. Retrieved 2023-08-16.
  2. ^ DE patent 289800, "Verfahren zur Darstellung der Oxyalkylderivate von Kohlenwasserstoffen", issued 1913-11-30, assigned to Bayer, Leverkusen 
  3. ^ Hirsh HL, Orsinger WH (January 1952). "Methylparafynol--a new type hypnotic. Preliminary report on its therapeutic efficacy and toxicity". American Practitioner and Digest of Treatment. 3 (1): 23–6. PMID 14903452.
  4. ^ Schaffarzick RW, Brown BJ (December 1952). "The anticonvulsant activity and toxicity of methylparafynol (dormison) and some other alcohols". Science. 116 (3024): 663–5. Bibcode:1952Sci...116..663S. doi:10.1126/science.116.3024.663. PMID 13028241.
  5. ^ Herz A (March 1954). "[A new type of hypnotic; unsaturated tertiary carbinols; experimental studies on therapeutic use of 3-methyl-pentin-ol-3 (methylparafynol)]". Arzneimittel-Forschung. 4 (3): 198–9. PMID 13159700.
  6. ^ Weaver LC, Alexander WM, Abreu BE (April 1961). "Anticonvulsant activity of compounds related to methylparafynol". Archives Internationales de Pharmacodynamie et de Therapie. 131: 116–22. PMID 13783544.
  7. ^ Hines RD (2002). The Pursuit of Oblivion. p. 327.
  8. ^ DE 959485, Grimene W, Emde H, issued 1957