- Synthesis Method for Candesartan Cilexetil Intermediate
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A synthesis method for a candesartan cilexetil intermediate represented by formula (II) is provided. The method includes (1) dissolving a compound represented by formula (IV) to an aprotic solvent to obtain a first mixed solution, and dissolving a phase transfer catalyst and an azidation reagent to water to obtain a second mixed solution; (2) dropping the first mixed solution to the second mixed solution for azidation reaction, and after the reaction is ended, standing and layering same to obtain an organic phase containing a compound represented by formula (V); (3) dropping the obtained organic phase containing the compound represented by formula (V) to tertiary butyl alcohol for rearrangement reaction, and after the reaction is ended, concentrating same to obtain a solid or oily material, then adding a crystallizing solvent to the obtained solid or oily material for recrystallization, and separating same to obtain a crystal.
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Page/Page column 0048-0050
(2022/03/31)
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- A 2 - ethoxy benzimidazole - 7 - carboxylic acid methyl ester
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The invention discloses a synthesis method of 2-ethoxy benzimidazole-7-carboxylic acid methyl ester. The problem that an existing process is not high in content and is very low in yield is solved. According to the synthesis method, 3-nitryl phthalic acid is used as a raw material, rearrangement is performed in a water solution after methyl esterification, acylation and re-nitridation, then tin powder is adopted to perform reduction and loop closing so as to obtain the 2-ethoxy benzimidazole-7-carboxylic acid methyl ester. By the adoption of the synthesis method, produced impurities are very little, the content is high, and the yield is also high.
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- PROCESS FOR PREPARATION OF CANDESART AN CILEXETIL SUBSTANTIALLY FREE OF DES-CANDESARTAN CILEXETIL IMPURITY
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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.
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Page/Page column 5
(2011/12/04)
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- PROCESS FOR PREPARING CANDESARTAN CILEXETIL
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A process for preparing candesartan cilexetil.
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Page/Page column 13-14
(2010/10/19)
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- METHOD FOR PRODUCTION OF CANDESARTAN
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The invention relates to novel methods for the production of Candesartan, or a protected form of Candesartan, a Candesartan salt or ester, compounds of application in said method, methods for production thereof, use thereof in said method, a novel polymorph of Candesartan cilexetil, a method for production and use thereof for production of a medicament.
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Page/Page column 18
(2010/11/08)
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- Nonpeptide Angiotensin II Receptor Antagonists. Synthesis and Biological Activity of Benzimidazolecarboxylic Acids
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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.
- Kubo, Keiji,Kohara, Yasuhisa,Imamiya, Eiko,Sugiura, Yoshihiro,Inada, Yoshiyuki,et al.
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p. 2182 - 2195
(2007/10/02)
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- Aspects of Tautomerism: Part X - Neighbouring Group Effects on the Structure and Reactivity Patterns of Acid Chlorides
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The influence of neighbouring groups on the structure and reactivity patterns of over one hundred acid chlorides derived from γ- and δ-keto acids, 1,2- and 1,3-dicarboxylic acid half-esters and diacid chlorides have been examined.Contrary to reports in the literature, text books and monographs, evidence has been obtained for the non-existence of tautomerism between the isomeric pairs of either acid chlorides or half-ester acid chlorides.ce.
- Bhatt, M. Vivekananda,El Ashry, Shaker H.,Somayaji, Vishwanatha
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p. 473 - 486
(2007/10/02)
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