Patent ID: 7772434

Claim:
A process for preparing a crystalline monohydrochloride salt of N-{2-[4-((R)-2-hydroxy-2-phenylethylamino)phenyl]ethyl}-(R)-2-hydroxy-2-(3-formamido-4-hydroxyphenyl)ethylamine wherein the crystalline monohydrochloride salt is characterized by an x-ray powder diffraction pattern having diffraction peaks at 2θ values of 15.98±0.2, 24.05±0.2, 26.08±0.2, and 28.13±0.2, the process comprising the steps of: (a) dissolving N-{2-[4-((R)-2-hydroxy-2-phenylethylamino)phenyl]ethyl}-(R)-2-hydroxy-2-(3-formamido-4-hydroxyphenyl)ethylamine in a polar solvent to form a first solution; and (b) adding between about 0.9 and about 1 molar equivalent of hydrochloric acid to form a second solution from which the crystalline monohydrochloride salt is formed.