| 摘要 |
<p>[Problem] To provide a method for producing a nitrogen- containing heterocyclic compound with high purity. [Solution] A method for producing a compound (A) of high purity, which comprises the step (a) and the step (b) described below. (a) a step wherein a mixture that contains the compound (A) and a compound (B) which is an impurity , is mixed with a solvent and a metal salt (b) a step wherein a mixture , which contains a smaller amount of the compound (B) in comparison to the mixture in step (a), is obtained in the form of a solution by filtering the mixed solution that is obtained in step (a) , or alternatively a mixture , which contains a smaller amount of the compound (B) in comparison to the mixture in step (a) is obtained by removing the solvent by distillation or carrying out crystallization after the filtration. (In the formulae each of R1 and R2 independently represents a hydrogen atom, a Ci.6. alkyl group or the like; R3 represents a hydrogen atom, a Ci.6 alkyl group or the like; and X represents a hydrogen atom or the like.)</p> |
