The present invention relates to the preparation of a β
2
adrenergic agonist in crystalline salt form. In particular the invention relates to preparation of a crystalline salt of compound (I)
in particular a crystalline monohydrochloride salt. The invention also relates to a new crystalline form (polymorph) of the monohydrochloride salt of compound (Ia) and a process for preparing it.
本发明涉及制备β2
肾上腺素受体激动剂的晶体盐形式。特别地,本发明涉及制备化合物(I)的晶体盐,特别是晶体单盐酸盐。本发明还涉及化合物(Ia)的单盐酸盐的一种新的晶体形态(多晶形式)及其制备方法。