R6890

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-triazaspirodecan-4-one, which is used in the synthesis of other drugs including spirilene, fluspirilene, spiramide, spiperone, RP-23618, spiroxatrine, L008716 and R5260.

Pharmacology

The pharmacology of R6890 is described as a nociceptin receptor agonist, although R6890 retains significant affinity at the mu opioid receptor. R6890 has affinities of 4, 75, and 10 nM for the mu, delta, and the total opioid receptor population, respectively.