PROBLEM TO BE SOLVED: To provide a crystal form of fluorine-containing amino acid prodrug which is stable in use environment as a pharmaceutical, and a method of producing the same.SOLUTION: This invention provides a crystal having at least one of (a)-(c) physical properties of benzene sulfonate represented by the following formula and a method of producing the same: (a) a peak at 2θ=4.4°, 17.1°, 22.7° and 25.7° in XRD(Cu-Kα) (b) a melting point of 173-178°C and (c) IR characteristic absorption band of 1763 cm-1, 1446 cm-1, 1257 cm-1, 1157 cm-1, 1072 cm-1, 1040 cm-1, 961 cm-1 and 733 cm-1.COPYRIGHT: (C)2015,JPO&INPIT【課題】含フッ素アミノ酸プロドラッグの医薬品としての使用環境で安定な結晶形及びその製造方法の提供。【解決手段】下記式で表されるベンゼンスルホン酸塩の(a)~(c)の物性の少なくとも1つを有する結晶及びその製造方法。(a)XRD(Cu-Kα)において、2θ=4.4度、17.1度,22.7度及び25.7度にピーク;(b)融点が173~178℃;(c)IR特性吸収帯が1763cm-1、1446cm-1、1257cm-1、1157cm-1、1072cm-1、1040cm-1、961cm-1及び733cm-1【選択図】図1
