Hydrochloric Acid → Tamsulosin Hydrochloride

Beteiligte Stoffe

Reaktionsschritte

2-Methoxy-5-(2-oxopropyl)-benzene sulfonamide (37.3 gm, 153.3 mmol), 2-(2-ethoxyphenoxy)-1-ethanamine (29.8 gm, 164.4 mmol) and methanol (250 mL) were taken into a one liter stainless steel flask and mixed well. Catalyst Raney nickel (8 gm) was added to the flask and the mixture hydrogenated at 50° C. at hydrogen pressure of 40 psi for 30 hrs. The catalyst was removed by filtration and solvent from the filtrate was distilled off completely at 50° C. under vacuum. The dark brown crude obtained was treated with methanolic hydrochloric acid (175 mL) at 0-5° C. under stirring. Tamsulosin hydrochloride formed as a solid was filtered, washed with ethyl acetate (200 mL), suspended in methanol (120 mL) and the methanol slurry filtered to obtain off white solid material. It was dried for 3 hrs at 80° C. to give racemic tamsulosin hydrochloride. Melting point 255-257° C., chemical purity of 98.8 area % (by HPLC) and R,S ratio of 51.45:48.55 (by chiral HPLC).

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