1-Piperazinecarboxylic acid, 6-(5-chloro-2-pyridinyl)-6,7-dihydro-7-oxo-5H-pyrrolo(3,4-b)pyrazin-5-yl ester 59878-63-6 6-(5-Chloro-2-pyridyl)-7-((1-piperazinyl)carbonyloxy)-6,7-dihydro(5H)pyrrolo(3,4-b)pyrazin-5-one N-Desmethylzopiclone