for the following products
6-(5-Chloropyrid-2yl) 5-hydroxy-7-oxo-5,6-dihydropyrrolo-[3,4-b]-pyrazine | 6-(5-Chloropyridin-2-yl)-7-hydroxy-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazin-5-one | Eszopiclone Impurity B and 6-(5-Chloro-2-pyridyl)-6,7-dihydro-7-hydroxy-5H-pyrrolo(3,4-b)pyrazin-5-one
