Legal status
Legal status
  • 2-(4-methoxyphenyl)-1-(1-pentyl-indol-3-yl)methanone
CAS Number
CompTox Dashboard (EPA)
ECHA InfoCard100.233.383 Edit this at Wikidata
Chemical and physical data
Molar mass321.420 g·mol−1
3D model (JSmol)
  • CCCCCn1cc(c2c1cccc2)C(=O)c3ccc(cc3)OC
  • InChI=1S/C21H23NO2/c1-3-4-7-14-22-15-19(18-8-5-6-9-20(18)22)21(23)16-10-12-17(24-2)13-11-16/h5-6,8-13,15H,3-4,7,14H2,1-2H3 checkY
 ☒NcheckY (what is this?)  (verify)

RCS-4, or 1-pentyl-3-(4-methoxybenzoyl)indole, is a synthetic cannabinoid drug sold under the names SR-19, BTM-4, or Eric-4 (later shortened to E-4), but originally, OBT-199.


RCS-4 is a potent cannabinoid receptor agonist, with EC50 values of 146 nM for human CB1 receptors, and 46 nM for human CB2 receptors.[2] All methoxyphenyl regioisomers, and N-butyl homologues of RCS-4 and its regioisomers also display potent agonist activities at CB1 and CB2 receptors.[2]


RCS-4 was banned in Sweden on 1 October 2010 as a hazardous good harmful to health, after being identified as an ingredient in "herbal" synthetic cannabis products.[3][4]

It was outlawed in Denmark on 11 March 2011.[5]

In August 2011, New Zealand added not only RCS-4 but also its 1-butyl homologue, and the 2-methoxybenzoyl isomers of both these compounds, to a temporary class drug schedule (i.e. equivalent to Class C but reviewed after 12 months, and with personal possession and use of small amounts decriminalised), which was newly created under the Misuse of Drugs Amendment Act 2011 passed a week earlier.[6][7][8]

As of October 2015 RCS-4 is a controlled substance in China.[9]

RCS-4 and related analogues detected in synthetic cannabis blends

See also


  1. ^ "Ustawa z dnia 15 kwietnia 2011 r. o zmianie ustawy o przeciwdziałaniu narkomanii ( Dz.U. 2011 nr 105 poz. 614 )". Internetowy System Aktów Prawnych. Retrieved 12 June 2011.
  2. ^ a b Banister SD, Stuart J, Conroy T, Longworth M, Manohar M, Beinat C, et al. (2015). "Structure–activity relationships of synthetic cannabinoid designer drug RCS-4 and its regioisomers and C4 homologues". Forensic Toxicology. 33 (2): 355–366. doi:10.1007/s11419-015-0282-9. S2CID 33994750.
  3. ^ Swedish Code of Statutes Regulation (2010:1086).
  4. ^ Swedish Code of Statutes Regulation (2010:1086). (pdf) Archived 2011-07-28 at the Wayback Machine
  5. ^ "Bilag 1 - Liste over euforiserende midler omfattet af bekendtgørelsen". Ministeriet for Sundhed og Forebyggelse. Archived from the original on 4 March 2016.
  6. ^ "Kronic ban passed by Parliament". The New Zealand Herald. NZPA. 4 August 2011. Retrieved 4 November 2011.
  7. ^ "Synthetic cannabis off shelves by Wednesday". The New Zealand Herald. NZPA. 9 August 2011. Retrieved 4 November 2011.
  8. ^ New Zealand Gazette. Tuesday 9 August 2011. Issue No 122, pp 3365-3366. Departmental Notices. Health. Misuse of Drugs Act 1975. Temporary Class Drug Notice.
  9. ^ "关于印发《非药用类麻醉药品和精神药品列管办法》的通知" (in Chinese). China Food and Drug Administration. 27 September 2015. Retrieved 1 October 2015.