As for this invention, as the field medicine it is expected, that it utilizes diffraction angle (2 0.2 ) it features that among other things it possesses diffraction peak in the 23.2 at the time of powder x-ray diffracting, it possesses A production control action, formula (1)So crystal of the 1.5D tartaric acid of the chemical compound which is displayed and diffraction angle (2 0.2 ) it features that among other things it possesses diffraction peak in the 17.1 , formula (1) crystal and other systems of two sulfates of chemical compound (1) the crystal multiformity and the like of the various salts and that salt of chemical compound is offered.本発明は、原薬として利用することが期待される、粉末X線回折において、回折角度(2θ±0.2°)23.2°に回折ピークを有することなどを特徴とする、Aβ産生抑制作用を有する、式(1)で表わされる化合物の1.5D-酒石酸塩の結晶、回折角度(2θ±0.2°)17.1°に回折ピークを有することなどを特徴とする、式(1)の化合物の二硫酸塩の結晶、その他の式(1)の化合物の種々の塩、その塩の結晶多形等を提供する。
