SYNTHESIS OF OPTICALLY PURE (R)-5-(2-AMINOPROPYL)-2-METHOXYBENZENESULFONAMIDE Russian patent published in 2011 - IPC C07C303/38 C07C311/37 A61K31/18 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for synthesis of (R)-5-(2-aminopropyl)-2-methoxybenzenesulfonamide. The method is realised from D-alanine and methoxybenzene through a Friedel-Crafts reaction and through (R)-1-(4-methoxy-3-sulfamoylphenyl)-2-trifluoroacetyl-aminopropane as an intermediate product. The method involves the following steps: (a) protecting amino groups of D-alanine, (b) reaction of the obtained D-alanine protected on atom N with methoxy benzene to obtain the corresponding 4'-methoxy-2-aminopropiophenol protected on the amino group, (c) complete reduction of oxo group of the formed 4'-methoxy-2-aminopropiophenol which is protected on the amino group to obtain the corresponding 1-(methoxyphenyl)propane-2-amine which is protected on the amino group, (d) chlorosulfonation of the obtained 1-(methoxyphenyl)propane-2-amine protected on the amino group and subsequent ammonolysis of the formed chlorosulfonyl group, and (e) removal of the protective amino group. Invention relates to a method of producing tamsulosin or tamsulosin hydrochloride, involving steps (a) to (e), a step for o-ethoxyphenoxyethylation of the amino group of (R)-5-(2-aminopropyl)-2-methoxybenzene and, if needed, a step for treating the obtained tamsulosin with HCl solution.

EFFECT: high optical purity of (R)-5-(2-aminopropyl)-2-methoxybenzenesulfonamide.

12 cl, 2 dwg, 9 ex