A crystal of a compound represented by the general formula (I) or a pharmacologically acceptable salt thereof has an excellent LCAT-activating effect and is useful as an active ingredient in a therapeutic or prophylactic agent for arteriosclerosis, arteriosclerotic heart disease, coronary heart disease (including heart failure, myocardial infarction, angina pectoris, cardiac ischemia, cardiovascular disturbance, and restenosis caused by angiogenesis), cerebrovascular disease (including stroke and cerebral infarction), peripheral vascular disease (including diabetic vascular complications), dyslipidemia, hypo-HDL-cholesterolemia, or renal disease, particularly, an anti-arteriosclerotic agent, wherein R1 is a hydrogen atom or a hydroxy group, and R is a 2-(trifluoromethyl)pyrimidin-5-yl group or a 5-(trifluoromethyl)pyrazin-2-yl group.
