AN IMPROVED PROCESS FOR THE PREPARATION OF (R) (-) TAMSULOSIN HYDROCHLORIDE

摘要

A process for the preparation of (R)(-) Tamsulosin hydrochloride [(R)(-)-5-[2-[[2-(o-ethoxy-phenoxy)ethyl]amino]-2-methylethyl]-2-methoxybenzenesulfonamide hydrochloride] of formula (III), The (R)(-) Tamsulosin hydrochloride of formula (III) produced by the process has an alpha-adrenergic blocking action and possesses a hypotensive activity and is used mainly for the treatment of benign prostatic hyperplasia (BPH). The process is directed to be high yielding, cost effective, easy to operate at industrial scale and does not involve the use of moisture sensitive, pyrophoric compounds. Importantly, the process would avoid unreacted contaminants in the final product and provide for isolating and obtaining the final product with good yield and purity. Advantageously, the process would not require the handling of hazardous reagents, such as LAH. The process is also selective, industrially favourable in that the same would use less amount of solvent, hence increase the plant capacity and will also require less manpower.