Potassium Carbonate → Eszopiclone

Participants

Reaction Steps

2.7 ml of a 40% aqueous solution of potassium carbonate were added to a solution of 2 g of (S)-zopiclone N-acetyl-D-aspartate in 18 ml of water in about 30 minutes at room temperature. The slurry was maintained for 1.5 hours at this temperature. The product was isolated by filtration and washed twice with 1.4 ml of water. The product was dried under vacuum at room temperature obtaining 1.29 g of eszopiclone (94%) as a white solid. e.e.: 99.8% by chiral HPLC. Water content: 0.9% w/w. Melting point: 198-201° C. [α]D20: +145° (c 1% w/w acetone).

Provenance & Evidence