- Practical syntheses of N-acetyl (E)-β-arylenamides
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A facile and practical method for the preparation of (E)-β- arylenamides [(E)-N-(1-arylprop-1-en-2-yl]acetamides] has been developed by reductive acetylation of the corresponding oximes with iron(II) acetate as the reducing reagent. Employment of hexamethylphosphoramide as the solvent was found to be critical for the high E/Z selectivity. The methodology has been applied in efficient syntheses of a key chiral intermediate of tamsulosin by asymmetric hydrogenation. Georg Thieme Verlag Stuttgart . New York.
- Cai, Zhihua,Liu, Guodu,Jiao, Guangjun,Senanayake, Chris H.,Tang, Wenjun
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p. 3355 - 3360
(2014/01/06)
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- Process for preparation of tamsulosin and its aralkylamine derivatives
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The present invention discloses a new process for the synthesis of tamsulosin and its aralkylamine derivatives, especially (R)-(?)-5-{2-[2-(2-alkoxyphenoxy)ethylamino]propyl}-2-alkoxybenzenesulfonamides having the following formula 1 (where R1 and R2 represent C1-C4 alkyl groups) and their hydrochloride thereof, and other various pharmaceutical used salts. Tamsulosin hydrochloride (R1=Et, R2=Me, in its hydrochloride salt form) is an antagonist of α-A adrenoceptors in the prostate. Tamsulosin?HCl occurs as white crystals, which melt with decomposition at approximately 230° C. It is sparingly soluble in water and in methanol, slightly soluble in glacial acetic acid and in ethanol, and practically insoluble in ether.
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Page/Page column 3; 6; 8
(2008/06/13)
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- Process for preparation of tamsulosin and its derivatives
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The present invention discloses a new process for the synthesis of tamsulosin derivatives of formula 1 (where R 1 and R 2 represent C 1 -C 4 alkyl groups) and their hydrochlorides and other pharmaceutically acceptable salts, comprising reacting the hydrochloride of sulphonamide 2 (where R represents C 1 -C 4 alkyl) with the ether compound 21 (where R' represents C 1 -C 4 alkyl and R" represents MeC 6 H 4 SO 2 or MeSO 2 ).
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Page/Page column 2; 5; 9-10; 14
(2008/06/13)
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- A METHOD OF PREPARATION OF (R)-(-)-5(2-AMINOPROPYL)-2-METHOXYBENZENESULFONAMIDE
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A method of preparation of (R)-(-)-5-(2-aminopropyl)-2-methoxybenzenesulfonamide of formula I and its use for production tamsulosin. A protective group is introduced to N-[(1R)-2-(4-methoxyphenyl)-1-methylethyl]-N- [(1 R)-1-phenylethyl)]amine and the resulting amide of formula IX is chlorosulfonated and the resulting sulfochloride is converted to a sulfonamide of formula X, from which the compound of formula I is obtained by hydrogenation.
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Page/Page column 8; 13
(2008/06/13)
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