300701-71-7Relevant academic research and scientific papers
Synthesis of enantiomerically pure desmethylzopiclone and determination of its absolute configuration
Hong, Yaping,Bakale, Roger P.,Fang, Qun K.,Xiang, Tingjian,Han, Zhengxu,McConville, Fran X.,Senanayake, Chris H.,Wald, Stephen A.
, p. 4623 - 4627 (2007/10/03)
Two synthetic methods have been established for the preparation of enantiomerically pure desmethylzopiclone, a metabolite of zopiclone. In Method A, (S)-desmethylzopiclone was prepared by demethylation of (S)-zopiclone with 1-chloroethyl chloroformate in high yield. Enantiomerically pure zopiclone (>99% ee) was obtained through a highly efficient resolution process in >36% overall yield. In Method B, racemic desmethylzopiclone was resolved with L-N-benzyloxycarbonyl phenylalanine (L-ZPA) followed by recrystallization in good yield. The absolute stereochemistry of the (+)-enantiomer was first determined to be the (S)-configuration by X-ray crystallography.
