With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.55112-42-0,4-Methyl-1-piperazinecarbonyl Chloride Hydrochloride,as a common compound, the synthetic route is as follows.,55112-42-0
EXAMPLE 3 Preparation of Zopiclone Charged 1.0 Kg (3.81 moles) of 6-(5-chloropyridyl-2-yl)-5-hydroxy-7-oxo-5,6-dihydro-pyrrolo[3,4b] pyrazine in 10.0 L. of methylene chloride and cooled the reaction mixture to 5-10 C. 1.0 Kg of 1-chlorocarbonyl-4-methylpiperazine hydrochloride was added at the same temperature. 1.22 Kg (12 moles) of triethyl amine was added to the reaction mixture followed by addition of N,N-dimethylamino pyridine (0.035Kg) at temperature 5-10 C. in two lots. Reaction mixture was heated to reflux and maintained for 2 hrs. Reaction mixture was cooled to room temperature and 4.5 L. of water was added at 25 C. The organic layer was separated and aqueous phase was extracted with methylene dichloride (2.0 L). The combined organic phase was washed with water (2.0 L), the organic phase was separated and concentrated at atmospheric pressure to obtain crude zopiclone. The crude zopiclone was recrystallized from ethyl acetate and further purified from isopropanol (Yield: 1.2 Kg). EXAMPLE 5; Recycling of (R)-zopiclone and its Conversion to Eszopiclone; (R)-Zopiclone (50 g) was dissolved in 10% HCl (500 ml) and heated up to 70 C. for 3 hrs. The progress of the reaction was monitored by TLC. After completion of the reaction, the reaction mass was cooled to room temperature, further cooled to 0 C. to 5 C. and filtered to obtain 6-(5-chloropyrid-2-yl)-5-hydroxy-7-oxo-5,6-dihydro-pyrrolo-[3,4-b] pyrazine.(22.4 g). Charged 22.4 g of 6-(5-chloropyridyl-2-yl)-5-hydroxy-7-oxo-5,6-dihydro-5H-pyrrolo [3,4-b] pyrazine in 250ml of methylene chloride and cooled the reaction mixture to 5-10 C. 22.4 g of 1-chlorocarbonyl-4-methylpiperazine hydrochloride was added at the same temperature. 27.32 g of triethyl amine was added to the reaction mixture followed by addition of N,N-dimethylamino pyridine (0.8 gms) at temperature 5-10 C. in two lots. Reaction mixture was heated to reflux and maintained for 2 hrs. Reaction mixture was cooled to room temperature and 100 ml. of water was added at 25 C. The organic layer was separated and aqueous phase was extracted with methylene chloride (50 ml). The combined organic phase was washed with water (50 ml), the organic phase was separated and concentrated at atmospheric pressure to obtain crude zopiclone. The crude zopiclone was recrystallised from ethyl acetate and further purified from isopropanol (Yield: 26.8 gms). The racemic zopiclone thus obtained was resolved using the method given in example 4 to obtain eszopiclone.
The synthetic route of 55112-42-0 has been constantly updated, and we look forward to future research findings.
Reference£º
Patent; Sawant, Shrikant Dattatraya; Naik, Anil Mahadev; Kavishwar, Girish Arvind; Kavishwar, Smita Girish; US2008/146800; (2008); A1;,
Piperazine – Wikipedia
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