title: 3-(3,5-Dimethoxyphenyl)-1,6-naphthyridine-2,7-diamines and related 2-urea derivatives are potent and selective inhibitors of the FGF receptor-1 tyrosine kinase.
abstract: A series of 3-aryl-1,6-naphthyridine-2,7-diamines and related 2-ureas were prepared and evaluated as inhibitors of the FGF receptor-1 tyrosine kinase. Condensation of 4,6-diaminonicotinaldehyde and substituted phenylacetonitriles gave intermediate naphthyridine-2,7-diamines, and direct reaction of the monoanion of these (NaH/DMF) with alkyl or aryl isocyanates selectively gave the 2-ureas in varying yields (23-93%). For the preparation of more soluble 7-alkylamino-2-ureas, a number of protecting groups for the 2-amine were evaluated (phthaloyl, 4-methoxybenzyl) following selective blocking of the 7-amine (trityl), but these were not superior to the (required) 2-tert-Bu-urea group itself. Direct alkylation of the anion of the (unprotected) 7-amino group with excess 4-(3-chloropropyl)morpholine in DMF gave low (10%) yields of the desired product, but alkylation of the 7-acetamido anion, followed by mild alkaline hydrolysis, raised this to 64%. 3-Phenyl analogues were nonspecific inhibitors of isolated c-Src, FGFR, and PDGFR tyrosine kinases, whereas 3-(2,6-dichlorophenyl) analogues were most effective against c-Src and FGFR, and 3-(3,5-dimethoxyphenyl) derivatives showed high selectivity for FGFR alone. A water-soluble (7-morpholinylpropylamino) analogue retained high FGFR potency (IC(50) 31 nM) and selectivity. Pairwise comparison of the 1, 6-naphthyridines and the corresponding known pyrido[2,3-d]pyrimidine analogues showed little differences in potency or patterns of selectivity, suggesting that the 1-aza atom of the latter is not important for activity. A 7-acetamide derivative inhibited the growth of FGFR-expressing tumor cell lines and was particularly potent against HUVECs (IC(50) 4 nM). This compound was also a very potent inhibitor of HUVEC microcapillary formation (IC(50) 0.01 nM) and Matrigel invasion (IC(50) 7 nM) and showed significant in vivo antitumor effects in a highly vascularized mammary adenocarcinoma 16/c model at nontoxic doses. The compounds are worthy of further evaluation as antiangiogenesis agents.
authors.affiliation: Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1000, New Zealand.
authors.forename: A M
authors.initials: AM
authors.lastname: Thompson
authors.forename: C J
authors.initials: CJ
authors.lastname: Connolly
authors.forename: J M
authors.initials: JM
authors.lastname: Hamby
authors.forename: S
authors.initials: S
authors.lastname: Boushelle
authors.forename: B G
authors.initials: BG
authors.lastname: Hartl
authors.forename: A M
authors.initials: AM
authors.lastname: Amar
authors.forename: A J
authors.initials: AJ
authors.lastname: Kraker
authors.forename: D L
authors.initials: DL
authors.lastname: Driscoll
authors.forename: R W
authors.initials: RW
authors.lastname: Steinkampf
authors.forename: S J
authors.initials: SJ
authors.lastname: Patmore
authors.forename: P W
authors.initials: PW
authors.lastname: Vincent
authors.forename: B J
authors.initials: BJ
authors.lastname: Roberts
authors.forename: W L
authors.initials: WL
authors.lastname: Elliott
authors.forename: W
authors.initials: W
authors.lastname: Klohs
authors.forename: W R
authors.initials: WR
authors.lastname: Leopold
authors.forename: H D
authors.initials: HD
authors.lastname: Showalter
authors.forename: W A
authors.initials: WA
authors.lastname: Denny
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D051379:Mice; D008815:Mice, Inbred Strains; D009287:Naphthyridines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor / Q000037:antagonists & inhibitors*; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured; D014508:Urea / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D004791:Enzyme Inhibitors; D009287:Naphthyridines; D017468:Receptors, Fibroblast Growth Factor; D014508:Urea; C496348:FGFR1 protein, human; C496349:Fgfr1 protein, mouse; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1