Bicyclic heteroarylpiperazines as selective brain penetrant 5-HT6 receptor antagonists.
Ahmed M,
Briggs MA,
Bromidge SM,
Buck T,
Campbell L,
Deeks NJ,
Garner A,
Gordon L,
Hamprecht DW,
Holland V,
Johnson CN,
Medhurst AD,
Mitchell DJ,
Moss SF,
Powles J,
Seal JT,
Stean TO,
Stemp G,
Thompson M,
Trail B,
Upton N,
Winborn K,
Witty DR.
Neurology and GI Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park, Third Avenue, Harlow, Essex CM19 5AW, UK.
Starting from the potent and selective but poorly brain penetrant 5-HT6 receptor antagonist SB-271046, a successful strategy for improving brain penetration was adopted involving conformational constraint with concomitant reduction in hydrogen bond count. This provided a series of bicyclic heteroarylpiperazines with high 5-HT6 receptor affinity. 5-Chloroindole 699929 combined high 5-HT6 receptor affinity with excellent brain penetration and also had good oral bioavailability in both rat and dog.
PMID: 16143522 [PubMed - indexed for MEDLINE]