Parahexyl Explained

Verifiedrevid:447736981
Iupac Name:3-n-hexyl- 7,8,9,10-tetrahydro- 6,6,9-trimethyl- 6H-dibenzo(b,d)pyran- 1-ol
Legal Br:F2
Legal Br Comment:[1]
Legal Ca:Schedule II
Legal Uk:Class B
Legal Us:Schedule I
Legal De:Anlage I
Legal Un:P I
Cas Number:117-51-1
Atc Prefix:none
Pubchem:8334
Kegg:C22779
Chemspiderid:8031
Unii:450N174F9W
C:22
H:32
O:2
Smiles:Oc2cc(cc1OC(C\3=C(/c12)CC(CC/3)C)(C)C)CCCCCC
Stdinchi:1S/C22H32O2/c1-5-6-7-8-9-16-13-19(23)21-17-12-15(2)10-11-18(17)22(3,4)24-20(21)14-16/h13-15,23H,5-12H2,1-4H3
Stdinchikey:OORFXDSWECAQLI-UHFFFAOYSA-N

Parahexyl (Synhexyl, n-hexyl-Δ3-THC, (C6)-Δ6a(10a)-THC) is a synthetic homologue of THC which was invented in 1941 during attempts to elucidate the structure of Δ9-THC, one of the active components of cannabis.[2] [3] [4]

Parahexyl is similar in both structure and activity to THC, differing only in the position of one double bond and the lengthening of the chain by one CH2 group to .[5] 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.[6] 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.[7] [8]

Parahexyl was made illegal under UN convention in 1971 on the basis of its structural similarity and similar effects profile to THC. Parahexyl was placed into the most restrictive Schedule I[9] as a compound with no medical use, despite the now-known medical uses for cannabinoids.

Isomerism

At least three isomers of parahexyl have been studied and are known to be active as cannabinoids. Parahexyl itself (i.e. the Δ6a(10a) isomer) has not had any significant use in scientific research since it was banned internationally in the early 1980s; however, the Δ8 and Δ9 isomers are both known to be cannabinoid receptor agonists, and Δ8-parahexyl has the code number JWH-124,[10] [11] while Δ9-parahexyl has been isolated from Cannabis plant material and assigned the name tetrahydrocannabihexol.[12]

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

Notes and References

  1. Web site: Anvisa . Brazilian Health Regulatory Agency . 2023-07-24 . RDC Nº 804 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial . Collegiate Board Resolution No. 804 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control. live . https://web.archive.org/web/20230827163149/https://www.in.gov.br/en/web/dou/-/resolucao-rdc-n-804-de-24-de-julho-de-2023-498447451 . 2023-08-27 . 2023-08-27 . . pt-BR . 2023-07-25.
  2. Adams R, Loewe S, Jelinek C, Wolff H . Tetrahydrocannabinol Homologs with Marihuana Activity. IX1. . Journal of the American Chemical Society . July 1941 . 63 . 7 . 1971–1973. 10.1021/ja01852a052 .
  3. Adams R, Harfenist M, Loewe S . New Analogs of Tetrahydrocannabinol. XIX . Journal of the American Chemical Society . 71 . 5. 1624–1628 . 1949 . 10.1021/ja01173a023 .
  4. http://www.cognitiveliberty.org/shulgin/adsarchive/parahexl.htm Ask Dr. Shulgin Online March 7, 2001
  5. Ono M, Shimamine M, Takahashi K, Inoue T . [Studies on hallucinogens. VII Synthesis of parahexyl] . ja . Eisei Shikenjo Hokoku. Bulletin of National Institute of Hygienic Sciences . 49 . 92 . 46–50 . 1974 . 4477495 .
  6. Fairchild MD, Jenden DJ, Mickey MR, Yale C . EEG effects of hallucinogens and cannabinoids using sleep-waking behavior as baseline . Pharmacology, Biochemistry, and Behavior . 12 . 1 . 99–105 . January 1980 . 6102770 . 10.1016/0091-3057(80)90422-0 . 24865915 .
  7. Book: Supniewski J . 1950 . Farmakologia . Warsaw . PZWL . 89.
  8. https://imgur.com/a/cEsFXig
  9. Report of the Technical Committee on Schedules I, II, III and I at the United Nations Conference for the adoption of a Protocol on Psychotropic Substances. 15 February 1971. E/CONF.58/L.47
  10. Martin BR, Jefferson R, Winckler R, Wiley JL, Huffman JW, Crocker PJ, Saha B, Razdan RK . Manipulation of the tetrahydrocannabinol side chain delineates agonists, partial agonists, and antagonists . The Journal of Pharmacology and Experimental Therapeutics . 290 . 3 . 1065–79 . September 1999 . 10454479 .
  11. Bow EW, Rimoldi JM . The Structure-Function Relationships of Classical Cannabinoids: CB1/CB2 Modulation . Perspectives in Medicinal Chemistry . 8 . 17–39 . 2016 . 27398024 . 4927043 . 10.4137/PMC.S32171 .
  12. Linciano P, Citti C, Russo F, Tolomeo F, Laganà A, Capriotti AL, Luongo L, Iannotta M, Belardo C, Maione S, Forni F, Vandelli MA, Gigli G, Cannazza G . Identification of a new cannabidiol n-hexyl homolog in a medicinal cannabis variety with an antinociceptive activity in mice: cannabidihexol . Scientific Reports . 10 . 1 . 22019 . December 2020 . 33328530 . 7744557 . 10.1038/s41598-020-79042-2 . 2020NatSR..1022019L .