摘要 |
<p>A method of preparing (3S)-l-[2-(2,3-dihydro-5-benzofuranyl)ethyl}-a,a-diphenyl-3- pyrrolidine acetamide hydrogen bromide, wherein 3-(S)-(I -carbamoyl- 1,1- diphenylmethyl)pyrrolidine or its salt with an organic acid is alkylated in the presence of an inorganic base with 5-(2-bromoethyl)-2,3-dihydrobenzofurane in a heterogeneous system of the solvents water and an organic solvent selected from C6 to C9 aliphatic, alicyclic or aromatic hydrocarbons, after separation of the two phases the crude darifenacin base is isolated, which is converted to the hydrobromide by addition of a C3 to C9 ketone or C3 to C9 alcohol and concentrated hydrobromic acid.</p> |