U-47700, also known as U4, pink heroin, pinky, and pink, is an opioidanalgesic drug developed by a team at Upjohn in the 1970s[1] which has around 7.5 times the potency of morphine in animal models.[2][3][4]
U-47700 is a structural isomer of the earlier opioid AH-7921[6] and the result of a great deal of work elucidating the quantitative structure–activity relationship of the scaffold. Upjohn looked for the key moieties which gave the greatest activity[7] and posted over a dozen patents on related compounds, each optimizing one moiety[8][9][10][11][12][13][14][15] until they discovered that U-47700 was the most active.[16]
U-47700 became the lead compound of selective kappa-opioid receptor ligands such as U-50488, U-51754 (containing a pyrrolidine rather than a dimethylamine substituent) and U-69,593, which share very similar structures.[17][18] Although not used medically, the selective kappa ligands are used in research.[19][20]
^Cheney BV, Szmuszkovicz J, Lahti RA, Zichi DA (December 1985). "Factors affecting binding of trans-N-[2-(methylamino)cyclohexyl]benzamides at the primary morphine receptor". Journal of Medicinal Chemistry. 28 (12): 1853–1864. doi:10.1021/jm00150a017. PMID2999404.
^Harper NJ, Veitch GB, Wibberley DG (November 1974). "1-(3,4-Dichlorobenzamidomethyl)cyclohexyldimethylamine and related compounds as potential analgesics". Journal of Medicinal Chemistry. 17 (11): 1188–1193. doi:10.1021/jm00257a012. PMID4416926.
^Szmuszkovicz J, Von Voigtlander PF (October 1982). "Benzeneacetamide amines: structurally novel non-m mu opioids". Journal of Medicinal Chemistry. 25 (10): 1125–1126. doi:10.1021/jm00352a005. PMID6128415.