From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Clinical data
ATC code
  • none
Legal status
Legal status
CAS Number
  • 117-51-1 checkY
    36482-24-3 (n-hexyl-Δ9-THC)
PubChem CID
Chemical and physical data
Molar mass328.496 g·mol−1
3D model (JSmol)

Parahexyl (Synhexyl, n-hexyl-Δ3-THC, (C6)-Δ6a(10a)-THC) is a synthetic homologue of THC, which was invented in 1949 during attempts to elucidate the structure of Δ9-THC, one of the active components of cannabis.[1][2]

Parahexyl is similar in both structure and activity to THC, differing only in the position of one double bond, and the lengthening of the 3-pentyl chain by one CH2 group to n-hexyl.[3] Parahexyl produces effects typical of other cannabinoid receptor agonists in animals. It has a somewhat higher oral bioavailability than THC itself but is otherwise very similar.[4] Presumably it acts as a CB1 agonist in the same way as THC but as there has been no research published using Parahexyl since the discovery of the CB1 receptor this has not been definitively confirmed.

Parahexyl was occasionally used as an anxiolytic in the mid-20th century, the dosage ranging from 5 mg to 90 mg.[5]

Parahexyl was made illegal under UN convention in 1982 on the basis of its structural similarity and similar effects profile to THC, despite never having had any recorded instances of recreational use by humans or illicit sale. Parahexyl was placed into the most restrictive Schedule 1 as a compound with no medical use, despite the now known medical uses for cannabinoids.


Dibenzopyran and monoterpenoid numbering of tetrahydrocannabinol derivatives
7 double bond isomers of parahexyl and their 30 stereoisomers
Dibenzopyran numbering Monoterpenoid numbering Number of stereoisomers Natural occurrence Convention on Psychotropic Substances Schedule
Short name Chiral centers Full name Short name Chiral centers
Δ6a(7)-parahexyl 9 and 10a 3-hexyl-8,9,10,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-1-ol Δ4-parahexyl 1 and 3 4 No unscheduled
Δ7-parahexyl 6a, 9 and 10a 3-hexyl-6a,9,10,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-1-ol Δ5-parahexyl 1, 3 and 4 8 No unscheduled
Δ8-parahexyl 6a and 10a 3-hexyl-6a,7,10,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-1-ol Δ6-parahexyl 3 and 4 4 No unscheduled
Δ9,11-parahexyl 6a and 10a 3-hexyl-6a,7,8,9,10,10a-hexahydro-6,6-dimethyl-9-methylene-6H-dibenzo[b,d]pyran-1-ol Δ1(7)-parahexyl 3 and 4 4 No unscheduled
Δ9-parahexyl 6a and 10a 3-hexyl-6a,7,8,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-1-ol Δ1-parahexyl 3 and 4 4 No unscheduled
Δ10-parahexyl 6a and 9 3-hexyl-6a,7,8,9-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-1-ol Δ2-parahexyl 1 and 4 4 No unscheduled
Δ6a(10a)-parahexyl 9 3-hexyl-7,8,9,10-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-1-ol Δ3-parahexyl 1 2 No Schedule I

Note that 6H-dibenzo[b,d]pyran-1-ol is the same as 6H-benzo[c]chromen-1-ol.

See also[edit]


  1. ^ Adams R, Harfenist M, Loewe S (1949). "New Analogs of Tetrahydrocannabinol. XIX". J. Am. Chem. Soc. 71 (5): 1624–1628. doi:10.1021/ja01173a023.
  2. ^ Ask Dr. Shulgin Online March 7, 2001
  3. ^ Ono M, Shimamine M, Takahashi K, Inoue T (1974). "[Studies on hallucinogens. VII Synthesis of parahexyl]". Eisei Shikenjo Hokoku. Bulletin of National Institute of Hygienic Sciences (in Japanese). 49 (92): 46–50. PMID 4477495.
  4. ^ Fairchild MD, Jenden DJ, Mickey MR, Yale C (January 1980). "EEG effects of hallucinogens and cannabinoids using sleep-waking behavior as baseline". Pharmacology, Biochemistry, and Behavior. 12 (1): 99–105. doi:10.1016/0091-3057(80)90422-0. PMID 6102770. S2CID 24865915.
  5. ^ Supniewski J (1950). Farmakologia. Warsaw: PZWL. p. 89.