アミノピリン-バルビタール-水系相図およびアミノピリン-バルビタール分子化合物の結晶定数について

抄録

To obtain basic data on crystallization of the molecular compound of aminopyrine and barbital from aqueous solution, the diagram of the ternary system, aminopyrine-barbital-water, was studied in the temperature range 0° to 98°. It was observed that lower critical temperature of layering of the aminopyrine-water system decreases with addition of barbital, that concentration ranges of aminopyrine and barbital in the solution which is in equilibrium with the molecular compound crystals, are narrowed with decrease of temperature and that concentration of barbital decreases more rapidly than that of aminopyrine. Therefore the best conditions to obtain the molecular compound are as follows : 1) excess amount of aminopyrine, 2) crystallization from concentrated solution, and 3) crystallization at high temperature. Furthermore, crystals of the molecular compound were examined by X-ray diffraction measurement; they belong to monoclinic system and the unit cell dimensions are : a 11.92, b 26.92, c 7.20 Å, β 97.3, with Z=4, space group is P2₁/c.