Method of preparing intermediate of salmeterol

摘要

A method of preparing an intermediate of salmeterol (Compound 1, 2-amino-1-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)ethanol) includes: reacting compound 2 with 2-methoxypropene in a first organic solvent to produce a reaction solution including compound 3, compound 2 including a 2-bromo precursor of Compound 1; reacting compound 3 with a nitrogen source to produce compound 4; reacting compound 4 with sodium borohydride in a second organic solvent to produce compound 5; and debenzylating compound 5 by ammonium formate/palladium-carbon catalytic transfer hydrogenation in a third organic solvent to produce Compound 1. A method of preparing salmeterol includes preparing Compound 1, and reacting Compound 1 to prepare salmeterol.

主权项

1. A method of preparing Compound 1, 2-amino-1-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)ethanol, the method comprising:
reacting Compound 2, 2-bromo-1-[4-hydroxy-3-(hydroxymethyl) phenyl]ethan-1-one, with 2-methoxypropene in a first organic solvent to produce a reaction solution comprising Compound 3, 2-bromo-1-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)ethanone; reacting Compound 3 with a nitrogen source in the reaction solution to produce Compound 4, 1-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-2-[methyl-1-phenylethylamino] ethanone; reacting Compound 4 with sodium borohydride in a second organic solvent to produce Compound 5, 1-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-2-[methyl-1-phenylethylamino]ethanol; and debenzylating Compound 5 by ammonium formate/palladium-carbon catalytic transfer hydrogenation in a third organic solvent to produce Compound 1.