title: Synthesis and biological evaluation of spirocyclic antagonists of CCR2 (chemokine CC receptor subtype 2).
abstract: Activation of chemokine CC receptors subtype 2 (CCR2) plays an important role in chronic inflammatory processes such as atherosclerosis, multiple sclerosis and rheumatoid arthritis. A diverse set of spirocyclic butanamides 4 (N-benzyl-4-(3,4-dihydrospiro[[2]benzopyran-1,4'-piperidin]-1'-yl)butanamides) was prepared by different combination of spirocyclic piperidines 8 (3,4-dihydrospiro[[2]benzopyran-1,4'-piperidines]) and γ-halobutanamides 11. A key step in the synthesis of spirocyclic piperidines 8 was an Oxa-Pictet-Spengler reaction of β-phenylethanols 5 with piperidone acetal 6. The substituted γ-hydroxybutanamides 11c-e were prepared by hydroxyethylation of methyl acetates 13 with ethylene sulfate giving the γ-lactones 14c and 14e. Aminolysis of the γ-lactones 14c and 14e with benzylamines provided the γ-hydroxybutanamides 15c-e, which were converted into the bromides 11c-e by an Appel reaction using polymer-bound PPh3. In radioligand binding assays the spirocyclic butanamides 4 did not displace the iodinated radioligand (125)I-CCL2 from the human CCR2. However, in the Ca(2+)-flux assay using human CCR2 strong antagonistic activity of butanamides 4 was detected. Analysis of the IC50-values led to clear relationships between the structure and the inhibition of the Ca(2+)-flux. 4g (4-(3,4-dihydrospiro[[2]benzopyran-1,4'-piperidin]-1'-yl)-N-[3,5-bis(trifluoromethylbenzyl)]-2-(4-fluorophenyl)butanamide) and 4o (N-[3,5-bis(trifluoromethyl)benzyl]-2-cyclopropyl-4-(3,4-dihydrospiro[[2]benzopyran-1,4'-piperidin]-1'-yl)butanamide) represent the most potent CCR2 antagonists with IC50-values of 89 and 17nM, respectively. Micromolar activities were found in the β-arrestin recruitment assay with murine CCR2, but the structure-activity-relationships detected in the Ca(2+)-flux assay were confirmed.
authors.affiliation: Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 48, 48149 Münster, Germany.
authors.forename: Ann Kathrin
authors.initials: AK
authors.lastname: Strunz
authors.affiliation: Leiden Academic Centre for Drug Research (LACDR), Leiden University, Division of Medicinal Chemistry, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Annelien J M
authors.initials: AJ
authors.lastname: Zweemer
authors.affiliation: Bayer Pharma AG, Global Drug Discovery-Lead Discovery Wuppertal, Aprather Weg 18a, Gebäude 456, D-42096 Wuppertal, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Weiss
authors.affiliation: Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 48, 48149 Münster, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Schepmann
authors.affiliation: Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 48, 48149 Münster, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Junker
authors.affiliation: Leiden Academic Centre for Drug Research (LACDR), Leiden University, Division of Medicinal Chemistry, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Laura H
authors.initials: LH
authors.lastname: Heitman
authors.affiliation: Bayer Pharma AG, Global Drug Discovery-Lead Discovery Wuppertal, Aprather Weg 18a, Gebäude 456, D-42096 Wuppertal, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Koch
authors.affiliation: Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 48, 48149 Münster, Germany; Cells-in-Motion Cluster of Excellence (EXC 1003-CiM), Westfälische Wilhelms-Universität Münster, Germany. Electronic address: wuensch@uni-muenster.de.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Wünsch
mesh_terms: D019390:Arrestins / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002460:Cell Line / Q000187:drug effects; D060326:Chemistry Techniques, Synthetic; D004353:Drug Evaluation, Preclinical / Q000379:methods; D006801:Humans; D020128:Inhibitory Concentration 50; D007457:Iodine Radioisotopes; D011869:Radioligand Assay; D054390:Receptors, CCR2 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013141:Spiro Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D000071557:beta-Arrestins
chemical_list: D019390:Arrestins; C515334:CCR2 protein, human; D007457:Iodine Radioisotopes; D054390:Receptors, CCR2; D013141:Spiro Compounds; D000071557:beta-Arrestins; D002118:Calcium
keywords: Appel reaction; Ca(2+) flux; Chemokine CC receptor subtype 2 (CCR2) antagonists; Ethylene sulfate; Oxa-Pictet–Spengler reaction; Polymer-bound triphenylphosphine; Receptor binding studies; Spirocyclic piperidines; Structure–activity-relationships; β-Arrestin recruitment