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公开(公告)号:US20060009641A1
公开(公告)日:2006-01-12
申请号:US11217931
申请日:2005-09-01
IPC分类号: C07D265/18
CPC分类号: C07D265/18
摘要: The instant invention describes a method for crystallizing (−)-6-chloro-4-cyclopropylethynyl-4-trifluoromethyl-1,4-dihydro-2H-3,1-benzoxazin-2-one from a solvent and anti-solvent solvent system and producing the crystalline product. The desired final crystal form, Form I, can be produced when using methanol or ethanol. Form II is isolated from 2-propanol and can be converted to the desired crystal form at low drying temperatures, such as between about a temperature of 40° C. and 50° C.