PURPOSE: To precipitate and separate the titled adenine useful as a coccidiostatic agent, selectively, by dissolving N6,9-disubstituted adenine containing N6,3-disubstituted adenine as impurity in hot glacial acetic acid, and adding hot water to the solution.
CONSTITUTION: N6,9-Disubstituted adenine of formulaI(R is H, 1W4C lower alkyl, or 5W7C aralkyl; R' is 1W4C lower alkyl or 5W7C aralkyl; Y and Z are H, F, Cl, etc.) containing N6,3-disubstituted adenine as an impurity is dissolved in hot glacial acetic acid (90W95°C), and hot water is added to the solution to precipitate the N6,9-disubstituted adenine selectively. The compound of formula is prepared by reacting the compound of formula II with the compound of formula III (X is Cl, etc.) in the presence of a phase transfer catalyst, and contains about 10W30% N6,3-disubstituted adenine as an impurity. The above method for the removal of the 3-substituted compound can be carried out easily and has high rate of removal compared with the conventional method using sulfuric acid.
ISOZAKI HIDEO
SHIROSHITA TOORU
SUZUKI JIROU
