| abstract |
The present invention relates to a crystallinenpolymorph of 2-[4-[2-[[(1 S ,2 R )-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino]ethyl]phenoxy]acetic acidnhaving strong diffraction peaks (diffraction angle: 2 ±n0.1°) at 10.8, 19.1, 19.3, 19.8, 20.6 and 27.0° in powdernx-ray diffraction pattern, which has potent β 2 - and β 3 -nadrenoceptor stimulating effects and is useful as an agentnfor relieving pain and promoting the removal of calculi innurolithiasis, and the like. For example, the crystallinenpolymorph can be prepared by hydrolyzing ethyln2-[4-[2-[[1 S ,2 R )-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino]ethyl]phenoxy]acetate phosphate by sodium hydroxide,nadding an aqueous phosphoric acid solution at 40 °C andnover, adding a mixed solvent of water and methanol ornmethanol to the resulting compound, and stirring thensuspension at 40 °C to reflux temperature for 30 minutesnto several hours. |