Highly Selective Treatment Of Benign Prostatic Hyperplasia Drug Harnal Synthesis And Process Research

Benign Prostatic Hyperplasia (abbreviation: BPH) is common and frequently occurs among elder men. BPH is the main reason of urethral obstruction. So the treatment for BPH has attracted the wide concerns.Tamsulosin Hydrochloride is a potent and selective 1A-adrenoceptor antagonist from Yamanouchi Co.Ltd in Japan. This drug is clinically used as the medication to ameliorate the dysuria associated with prostatic hypertrophy.It has been reported that there existed many synthetic routes about the preparation of Tamsulosin Hydrochloride. Through analyzing theoretically and trying practically, the objective compound was synthesized over 11 steps (and 2 sideway steps) operation. The overyield is 2.2%. Its structure was identified by the data of IR, UV-VIS, 1H-NMR, 13C-NMR and MS, et al.The preparation methods of 7 intermediates (TH-1, TH-2, TH-3, TH-4, (R)-TH-5, (R)-TH-6, (R)-1) were investigated respectively. The 1-(p-methoxyp-henyl)-2-propylamine was improved in the method of synthesis.In this paper, The resolution of 1-(p-methoxyphenyl)-2-propylamine was emphasized. l-(p-methoxyphenyl)-2-propylamine was formed salt with dextrotartatic acid. Then recrstallation, alkaline hydrolysis and a second preparation of salt were operated in order .The laevo-l-(p-methoxyp-henyl)-2-propylamine could be obtained after repeating the same steps over many times.