Synthesis
About 80% of the solvent volume was distilled at atmospheric pressure. Ethyl acetate (190 ml) was added and the organic solution was washed with aqueous HCl (2M, 114 ml) to give an ethyl acetate solution of (XV). The ethyl acetate solution of (XV) was added to an acetonitrile (760 ml) suspension of cinchonidine (55.94 g, 0.19 mol) at 60C. The resulting mixture was stirred at 60 C for 10 min, then cooled to 22 C and filtered. The solid was recrystallized from isopropanol (1500 ml) and dried to give 24.8 g (29% yield) of white solid cinchonidine dihydrochloride.
