Spirochlorphine

 The following information was compiled in October 2025 and is subject to change as new research is conducted and as new information becomes available:

Description: Spirochlorphine (R-6890) is a novel synthetic opioid characterized as an “orphine” analogue with a spiropiperidine group. It bears structural similarity to other benzimidazolones (e.g., brorphine, chlorphine, N-propionitrile chlorphine). Spirochlorphine was first researched in the 1970s as a narcotic analgesic and has since been reported in drug materials in North America and Europe.^1,2 Spirochlorphine was first identified by our laboratory in May 2025 and later confirmed after acquiring standard reference material.

Sample Source: Public Health & Harm Reduction Collaborators

Sample Appearance: White solid material, purple solid powder

Pharmacology: Spirochlorphine is reported to a potent mu-opioid receptor agonist and binding affinity and analgesic potency have been studied in animal models (IC₅₀ = 4.6 nM, ED₅₀ = 0.54 µmol/kg).²

Toxicology: Spirochlorphine has been detected in one toxicology case to date at the CFSRE.

Drug Materials: Spirochlorphine has been detected in 15 drug materials to date at the CFSRE.

Demographics / Geographics: Samples originated from Illinois and New England. Spirochlorphine was identified along and alongside other synthetic opioids (e.g., fentanyl, N-pyrrolidino ethylene isotonitazene).

Legal Status: Spirochlorphine is not currently scheduled in the United States.

Class:

Opioid

Appearance:

White solid material

Formula:

C21H24ClN3O

MW:

369.9

[M+]:

369

[M+H]+:

370.1681

IUPAC:

8-[1-(4-chlorophenyl)ethyl]-1-phenyl-1,3,8-triazaspiro[4.5]decan-4-one

Report Date:

October 14, 2025