139481-28-0Relevant academic research and scientific papers
PROCESS FOR PREPARATION OF CANDESART AN CILEXETIL SUBSTANTIALLY FREE OF DES-CANDESARTAN CILEXETIL IMPURITY
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Page/Page column 5-6, (2011/12/04)
The present invention provides a process for preparation of candeartan cilexetil substantially free of 2,3-dihydro-2-oxo-3-[[2'-(2H-tetrazol-5-yl)[l,l-biphenyl]-4- yl]methyl]-l-[[(cyclohexyloxy)carbonyl]oxy]ethylester-lH-benzimidazole-7- carboxylate (des-candesartan cilexetil) impurity.
New practical synthesis of the key intermediate of candesartan
Porcs-Makkay, Marta,Mezei, Tibor,Simig, Gyula
, p. 490 - 493 (2012/12/31)
The development of a new, practical synthesis of methyl 3-amino-N-(2′-cyanobiphenyl-4-yl)methyl]anthranilate, key intermediate of candesartan, is described, starting from methyl anthranilate. The features of our approach are as follows: (i) introduction of the 3-nitro group by acid catalysed rearrangement of the corresponding methyl N-nitroanthranilate; (ii) introduction of a (2′-cyanobiphenyl-4-yl)methyl side chain by N-alkylation of the appropriate N-nitroanthranilic acid derivative. In the most efficient procedure methyl N,3-dinitroanthranilate was N-alkylated with 4′-bromomethyl-biphenyl-2-nitrile. Catalytic reduction of the aromatic nitro group was accompanied with the removal of the N-nitro function to afford the required key intermediate in good yield.
CRYSTAL AND PROCESS FOR PRODUCING THE SAME
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Page 16-17; 18, (2010/02/06)
A process for producing crystals of 2-ethoxy-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-benzimdazole-7-carboxylic acid (compound (I)), characterized by dissolving or suspending the compound (I) or a salt thereof in a solvent comprising an aprotic polar solvent and crystallizing it. By the process, the contaminants which are contained in the compound (I) or its salt and are difficult to remove, such as tin compounds, analogues of the compound (I), and a residual organic solvent, can be easily removed. Crystals of the compound (I) can be efficiently and easily mass-produced in high yield on an industrial scale.
Nonpeptide Angiotensin II Receptor Antagonists. Synthesis and Biological Activity of Benzimidazolecarboxylic Acids
Kubo, Keiji,Kohara, Yasuhisa,Imamiya, Eiko,Sugiura, Yoshihiro,Inada, Yoshiyuki,et al.
, p. 2182 - 2195 (2007/10/02)
A series of 2-substituted-1--1H-benzimidazole-7-carboxylic acids was prepared from the key intermediate 3-amino-2-amino>benzoate (6a-c) in order to clarify the structure-activity relationships of various analogues of 2-butyl-1-methyl>-1H-benzimidazole-7-carboxylic acid (CV-11194), a potent and long acting angiotensin II (AII) receptor antagonist.The AII antagonistic activity of the benzimidazoles was investigated by in vitro assays, which included an AII receptor binding assay and AII-induced vasocontraction assay, as well as by in vivo assays such as an AII-induced pressor response in rats.Most of the benzimidazoles showed high affinity for the AII receptor (IC50 value, 10-6-1--7 M) and inhibited the AII-induced pressor response at 1 or 3 mg/kg po, and the effects were more potent than those of CV-11194 and DuP 753.The structure-activity relationship studies on the binding affinity and the inhibition of AII-induced pressor response suggested that straight chains of a certain length (e.g., ethoxy groups, ethyl groups) were the best as substituents at the 2-position and that their steric factors, lipohilicity, and electronic effects affected the potency of the AII antagonistic action.Both a carboxyl group at the 7-position and a tetrazole ring at the 2'-position were particularly important for potent and orally active AII antagonistic activity and a long-acting hypotensive effect.The representative compound, 2-ethoxy-1-methyl>-1H-benzimidazole-7-carboxylic acid (26b, CV-11974), inhibited the specific binding of AII to bovine adrenal cortical membrane with an IC50 value of 1.1*10-7 M.The AII-induced contraction of rabbit aortic strips was antagonized by CV-11974 (IC50 value, 3.0*1--10 M).Oral administration of CV-11974 to conscious normatensive rats at 1 mg/kg resulted in long-lasting inhibition of the AII-induced pressor response.CV-11974 at 0.1-1 mg/kg iv reduced blood pressure dose-dependently in spontaneously hypertensive rats.
