R6890, sometimes known as spirochlorphine, is an opioid analgesic and a member of the spiropiperidine family of agents. The first known mention of this compound was in 1977. Other examples of agents from this class are Ro64-6198 and Ro65-6570. Brorphine also has a similar structure.
A precursor chemical used in the synthesis of R6890 is 1-phenyl-1,3,8-triazaspiro(4,5)decan-4-one (also known as spirodecanone), which is used in the synthesis of other drugs including spirilene, fluspirilene, spiramide, spiperone, RP-23618, spiroxatrine, L008716 and R5260.
The pharmacology of R6890 is described as a nociceptin receptor (NOP) agonist, although R6890 retains significant affinity at the mu opioid receptor. R6890 has affinities (K<sub>i</sub> values) of 4, 75, and 10 nM for the mu, delta, and the total opioid receptor population, respectively.