7-Hydroxy-furo[3,4-b]pyrazin-5-one is a derivative of 6-(5-Chloro-2-pyridyl)-6,7-dihydro-7-hydroxy-5H-pyrrolo[3,4-b]pyrazin-5-one (C379925) which is an impurity of Eszopiclone
Identification: 1H NMR (D2O) and MSTLC Conditions: C18; Acetonitrile : Water = 9 : 1; Visualized with UV; Single Spot, Rf = 0.50.1H NMR and MS conform to structure.