1. Dual neurokinin NK(1)/NK(2) antagonists: N-[(R,R)-(E)-1-arylmethyl-3-(2-oxo-azepan-3-yl)carbamoyl]allyl-N-methyl-3,5-bis(trifluoromethyl)benzamides and 3-[N'-3,5-bis(trifluoromethyl)benzoyl-N-arylmethyl-N'-methylhydrazino]-N-[(R)-2-oxo-azepan-3-yl]propionamides
M Gerspacher, L La Vecchia, R Mah, A von Sprecher, G P Anderson, N Subramanian, K Hauser, H Bammerlin, S Kimmel, V Pawelzik, K Ryffel, H A Ball Bioorg Med Chem Lett. 2001 Dec 3;11(23):3081-4. doi: 10.1016/s0960-894x(01)00631-x.
Based on the structure of N-[(R,R)-(E)-1-(4-chlorobenzyl)-3-(2-oxoazepan-3-yl)carbamoyl]allyl-N-methyl-3,5-bis(trifluoromethyl)benzamide (1), attempts to improve the NK(2) affinity have resulted in the discovery of N-[(R,R)-(E)-1-(3,4-dichlorobenzyl)-3-(2-oxoazepan-3-yl)carbamoyl]allyl-N-methyl-3,5-bis(trifluoromethyl)benzamide (9, DNK333) exhibiting a 5-fold improved affinity to the NK(2) receptor in comparison to 1. Simplification of the structure via elimination of a chiral centre led to 3-[N'-3,5-bis(trifluoromethyl)benzoyl-N-(3,4-dichlorobenzyl)-N'-methylhydrazino]-N-[(R)-2-oxo-azepan-3-yl]propionamide (22), a potent and fairly balanced NK(1)/NK(2) antagonist.
2. Pharmacological characterization of ZD6021: a novel, orally active antagonist of the tachykinin receptors
W L Rumsey, et al. J Pharmacol Exp Ther. 2001 Jul;298(1):307-15.
The tachykinins, substance P, neurokinin A, and neurokinin B, have been implicated in many diseases. The present study evaluated the pharmacological properties of a novel tachykinin antagonist ZD6021 [3-cyano-N-((2S)-2-(3,4-dichlorophenyl)-4-[4-[2-(methyl-(S)-sulfinyl)-phenyl]piperidino]butyl)-N-methyl-]-napthamide]. The affinity (K(i)) of ZD6021 for the cloned human neurokinin (NK)1, NK2, and NK3 receptors was 0.12 +/- 0.01, 0.64 +/- 0.08, and 74 +/- 13 nM, respectively. Mucin secretion by Chinese hamster ovary cells transfected with the human NK1 receptor was dose dependently inhibited by ZD6021: pIC(50) = 7.6 +/- 0.1. For NK1 and NK2 receptors, the agonist concentration-response curves using isolated tissues were displaced rightward in the presence of ZD6021: rabbit pulmonary artery, pA2 = 8.7 and 8.5; human pulmonary artery and bronchus, pKB = 8.9 +/- 0.4 and 7.5 +/- 0.2, at 10(-7) M, respectively. Senktide-induced contractions of isolated guinea pig ileum were also blocked by low concentrations of ZD6021. Oral administration of ZD6021 to guinea pigs dose dependently attenuated tracheal extravasation of plasma proteins induced by the NK1 receptor agonist Ac-[Arg6,Sar9,Met(O2)11]-SP(6-11), ED50 = 0.8 micromol/kg, and bronchoconstriction, elicited by the NK2 receptor agonist [beta-Ala8]-NKA(4-10), ED50 = 20 micromol/kg. Potency was unaffected by feeding. After oral administration of ZD6021, the time to peak activity was 150 min for the NK1 receptor and 60 min for the NK2 receptor with pharmacodynamic half-lives of 280 and 458 min, respectively. These data indicate that ZD6021 is a potent, orally active antagonist of all three tachykinin receptors. This compound may be useful for future studies of tachykinin-related pathology such as asthma.
3. Design and synthesis of 3,5-disubstituted benzamide analogues of DNK333 as dual NK1/NK2 receptor probes
Venkat Manoj Swarna, Bradley J Undem, Vijaya L Korlipara Bioorg Med Chem Lett. 2007 Feb 15;17(4):890-4. doi: 10.1016/j.bmcl.2006.11.064. Epub 2006 Dec 1.
N-[(R,R)-(E)-(3,4-dichlorobenzyl)-3-(2-oxoazepan-3-yl)carbamoyl]allyl-N-methyl-3,5-bis(trifluoromethyl)benzamide (DNK333, 1b) has been reported to be a potent and balanced dual neurokinin (tachykinin) receptor antagonist. A recent clinical trial using DNK333 has shown that it blocks the NKA-induced bronchoconstriction in patients with asthma. A series of six analogues 3-8 derived from modification of 3,5-bis(trifluoromethyl)benzamide moiety of DNK333 has been synthesized to serve as the dual NK(1)/NK(2) receptor probes. The 3,5-dinitro substituted benzamide compound 3 was found to possess potent and balanced dual NK(1)/NK(2) receptor antagonist activities (pK(b)=8.4 for the NK(1) receptors, pK(b)=7.87 for the NK(2) receptors) in the functional assay using guinea pig trachea. Furthermore, SAR analysis suggests that steric, electronic, and lipophilic characteristics of substituents in the benzamide region of DNK333 have a crucial effect on both the NK(1) and NK(2) receptor antagonist activities.
