180161-14-2Relevant articles and documents
Synthesis and structure-activity relationships of novel histamine H 1 antagonists: Indolylpiperidinyl benzoic acid derivatives
Fonquerna, Silvia,Miralpeix, Montse,Pagès, Lluís,Puig, Carles,Cardús, Arantxa,Antón, Francisca,Cárdenas, álvaro,Vilella, Dolors,Aparici, Mónica,Calaf, Elena,Prieto, José,Gras, Jordi,Huerta, Josep M.,Warrellow, Graham,Beleta, Jorge,Ryder, Hamish
, p. 6326 - 6337 (2007/10/03)
A series of indolylpiperidinyl derivatives were prepared and evaluated for their activity as histamine H1 antagonists. Structure-activity relationship studies were directed toward improving in vivo activity and pharmacokinetic profile of our first lead (1). Substitution of fluorine in position 6 on the indolyl ring led to higher in vivo activity in the inhibition of histamine-induced cutaneous vascular permeability assay but lower selectivity toward 5HT2 receptor. Extensive optimization was carried out within this series and a number of histamine H1 antagonists showing potency and long duration of action in vivo and low brain penetration or cardiotoxic potential were identified. Within this novel series, indolylpiperidines 15, 20, 48, 51 and 52 exhibited a long half-life in rat and have been selected for further preclinical evaluation.
3-(4-Fluoropiperidin-3-yl)-2-phenylindoles as high affinity, selective, and orally bioavailable h5-HT2A receptor antagonists
Rowley,Hallett,Goodacre,Moyes,Crawforth,Sparey,Patel,Marwood,Patel,Thomas,Hitzel,O'Connor,Szeto,Castro,Hutson,Macleod
, p. 1603 - 1614 (2007/10/03)
The development of very high affinity, selective, and bioavailable h5-HT2A receptor antagonists is described. By investigation of the optimal position for the basic nitrogen in a series of 2-phenyl-3-piperidylindoles, it was found that with the basic nitrogen at the 3-position of the piperidine it was not necessary to further substitute the piperidine in order to obtain good binding at h5-HT2A receptors. This meant the compounds no longer had high affinity at the IKr potassium channel, an issue with previous series of 2-aryl-3-(4-piperidyl)indoles. Improvements could be made to oral bioavailability in this series by reduction of the pKa of the basic nitrogen, by adding a fluorine atom to the piperidine ring, leading to 3-(4-fluoropiperidin-3-yl)-2-phenyl-1H-indole (17). Metabolic studies with this compound identified oxidation at the 6-position of the indole as a major route in vitro and in vivo in rats. Blocking this position with a fluorine atom led to 6-fluoro-3-(4-fluoropiperidin-3-yl)-2-phenyl-1H-indole (22), an antagonist with 0.06 nM affinity for h5-HT2A receptors, with bioavailability of 80% and half-life of 12 h in rats.
Neighboring group participation of the indole nucleus: An unusual DAST-mediated rearrangerment reaction
Hallett, David J.,Gerhard, Ute,Goodacre, Simon C.,Hitzel, Laure,Sparey, Timothy J.,Thomas, Steven,Rowley, Michael,Ball, Richard G.
, p. 4984 - 4993 (2007/10/03)
A rearrangement reaction involving the indole nucleus was investigated using stereochemical markers and low-temperature NMR experiments. Treatment of(3S,4S)-3-hydroxy-4-(2-phenyl-1H-indol-3-yl)-piperidine-1-carboxylic acid benzyl ester (> 90% ee) with diethylaminosulfur trifluoride gave stereospecifically (3S,4S)-4-fluoro-3-(2-phenyl-1H-indol-3-yl)-piperidine-1-carboxylic acid benzyl ester (> 90% ee) with complete regioselectivity. The initial formation of a reactive spirocyclopropyl-3H-indole intermediate is believed to be responsible for the stereo- and regiochemical outcome of the reaction.
