Synthetic Route of 5780-66-5,Some common heterocyclic compound, 5780-66-5, name is Pyrazine-2-carbaldehyde, molecular formula is C5H4N2O, 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.
Method 54; Pvrazine-2-carboxaldehyde oxime A IN solution of lithium aluminium hydride in THF (73. 8ml, 73.8mmol) was added to a suspension of methyl pyrazine-2-carboxylate (20g, 145mmol) in anhydrous THF (300. 0ml) at-78°C keeping the reaction temperature below-72°C. On completion of addition the reaction mixture was left to stir at-78°C for a further 20 minutes and then quenched with glacial acetic acid (20. 0ml). The resulting mixture was warmed to room temperature and the volatiles removed by evaporation. The residue was dissolved in 3N hydrochloric acid (116ml) and extracted with DCM. The extracts were combined, washed with saturated aqueous sodium hydrogen carbonate solution and the solvent evaporated. The residue was purified by chromatography on silica gel eluting with DCM/diethylether (100: 0 then 80: 20 and then 0: 100) to give pyrazine-2-carboxaldehyde (15.67g, 100percent). This was immediately dissolved in chloroform (200ml) cooled to 0°C and hydroxylamine mono-hydrochloride (11. 02g, 159. 5mmol) and triethylamine (24. 2ml, 117. 4mmol) were added. The reaction mixture was then stirred at ambient temperature for 0.5 hour, and the solvent removed by evaporation. The residue suspended in diethylether (500ml) and the insolubles removed by filtration. The filtrate was evaporated and the residue purified by chromatography eluting with DCM/diethylether (100: 0 then 80: 20 and then 0: 100) to give the title compound (5. 5g, 31percent) as a solid. NMR (DMSO-d6) : 8.15 (s, 1H), 8.62 (dd, 2H), 8. 99 (s, 1H).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Pyrazine-2-carbaldehyde, its application will become more common.
Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2005/40159; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem