Acyclovir Impurity K: 2,2'-[Methylenediimino] bis[9-[2-hydroxy-ethoxy)methyl]-1-9-dihydro-6H-purin-6-one;Aciclovir EP Impurity K;2,2'-(methylenebis(azanediyl))bis(9-((2-hydroxyethoxy)methyl)-1H-purin-6(9H)-one);Valacyclovir EP Impurity L;Acyclovir EP Impurity K;Acyclovir Impurity 14（Acyclovir EP Impurity K）;Acyclovir impurity 8/Acyclovir EP Impurity K/Acyclovir N-Methylene Dimer/Valaciclovir EP Impurity L/2,2-(methylenebis(azanediyl))bis(9-((2-hydroxyethoxy)methyl)-1H-purin-6(9H)-one;2,2'-(methylenebis(azanediyl))
