title: trans-2,3-dihydroxy-6a,7,8,12b-tetrahydro-6H-chromeno[3,4-c]isoquinoline: synthesis, resolution, and preliminary pharmacological characterization of a new dopamine D1 receptor full agonist.
abstract: We report the synthesis of trans-2,3-dihydroxy-6a,7,8,12b-tetrahydro-6H-chromeno[3,4-c]isoquinoline hydrochloride 6 and the resolution of its enantiomers. This new compound is an oxygen bioisostere of the potent dopamine D1-selective full agonist dihydrexidine. The initial synthetic approach involved, as a key step, a Suzuki coupling between a chromene triflate and a boronate ester, followed by isoquinoline formation and reduction of the resulting isoquinoline. Subsequently, a more efficient route was developed that involved conjugate addition of an aryl Grignard reagent to a 2-nitrochromene. The title compound possessed high affinity (Ki=20-30 nM) for porcine D1-like receptors in native striatal tissue and full intrinsic activity at cloned human dopamine D1 receptors but had much lower affinity at dopamine D2-like receptors (Ki=3000 nM). The binding and functional properties of this compound illustrate again the utility of constructing dopamine D1 agonist ligands around the beta-phenyldopamine pharmacophore template.
authors.affiliation: Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Cueva
authors.forename: Gianfabio
authors.initials: G
authors.lastname: Giorgioni
authors.forename: Russell A
authors.initials: RA
authors.lastname: Grubbs
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Chemel
authors.forename: Val J
authors.initials: VJ
authors.lastname: Watts
authors.forename: David E
authors.initials: DE
authors.lastname: Nichols
mesh_terms: D000818:Animals; D001578:Benzopyrans / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001667:Binding, Competitive; D002460:Cell Line; D003342:Corpus Striatum / Q000378:metabolism; D018360:Crystallography, X-Ray; D000242:Cyclic AMP / Q000096:biosynthesis; D006801:Humans; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D015394:Molecular Structure; D010617:Phenanthridines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011619:Psychotropic Drugs / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D017447:Receptors, Dopamine D1 / Q000819:agonists*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013552:Swine
chemical_list: C516224:2,3-dihydroxy-6a,7,8,12b-tetrahydro-6H-chromeno(3,4-c)isoquinoline; D001578:Benzopyrans; D007546:Isoquinolines; D010617:Phenanthridines; D011619:Psychotropic Drugs; D017447:Receptors, Dopamine D1; C061532:dihydrexidine; D000242:Cyclic AMP