Bopindolol

Bopindolol (INN) is a beta blocker. It is an ester which acts as a prodrug for its active metabolite 4-(3-t-butylamino-2-hydroxypropoxy)-2-methylindole.

Synthesis
The reaction of 4-Hydroxy-2-methylindole [35320-67-3] (1) with epichlorohydrin in the presence of lye led to 2-methyl-4-(oxiran-2-ylmethoxy)-1H-indole [62119-47-5] (2). Addition of tert-butylamine led to 4-(2-Hydroxy-3-tert-butylaminopropoxy)-2-methylindole [23869-98-9] (3). Ester formation with benzoic anhydride [93-97-0] (4) in the presence of hexamethylphosphoric acid triamide [680-31-9] completed the synthesis of Bopindolol (5).