These common heterocyclic compound, 77112-52-8, name is Ethyl imidazo[1,2-a]pyrazine-2-carboxylate, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. name: Ethyl imidazo[1,2-a]pyrazine-2-carboxylate
To a well stirred suspension of the ester obtained from step-1 (10 g, 52.3 mmol) in dioxane (400 ml) was added lithium borohydride (2 eqv) at 25 C. and the resulting reaction mixture was allowed to stir at the same temperature for 10 minutes. It was then warmed to 60 C. and kept at this temperature for 20 minutes (. Higher temperature and more reaction time reduce the yield and quality of reaction). Reaction mixture was then cooled to 0 C., acidified with 1N HCl and dioxane was completely evaporated under reduced pressure. Residue was taken in dichloromethane (200 ml), TEA (4eqv) and Boc-anhydride (1.2 eqv) was added to it and the resulting reaction mixture was allowed to stir at 25 C. for 16 hrs. Organic layer was washed with water and brine and finally dried over sodium sulfate. Evaporation of organic layer gave the crude product which was purified by column chromatography (70% ethyl acetate in hexane). Yield: 27%
The synthetic route of Ethyl imidazo[1,2-a]pyrazine-2-carboxylate has been constantly updated, and we look forward to future research findings.
Reference:
Patent; GRUENENTHAL GmbH; US2009/186899; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem