PURPOSE: To obtain a novel compound which is useful in selective separation and extraction of metallic ion as a solvent extraction separator for calcium ion.
CONSTITUTION: This calix[4]arene derivative is represented by formula I (X1, X2 are each H, a 1-18C alkyne; R1, R2 are each an alkyne, a (substituted) phenyl). The compound of formula I is obtained, for example, by allowing a calixarene of formula II ((n) is 3-8) to reast with an acid chloride under appropriate conditions to form the diester, followed by diamidation and hydrolysis or the ester to free carboxylic acid. The compound of formula I has high ability to extract calcium ion, thus, attains selective calcium ion extraction even when other alkaline earth metal ions such as Mg, Sr or Ba are present. This derivative is excellent in stability, can be synthesized in a large amount inexpensively, thus is useful in the fields where the separation of calcium ion is needed, for example, chemistry, biochemistry and industrial fields.
FUJIMOTO KIYOSHI
OGATA MICHIKO
HARADA YOSHIFUMI
