Reference of 121246-96-6, These common heterocyclic compound, 121246-96-6, name is 3-Chloropyrazine-2-carbaldehyde, 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.
2,2,6,6-Tetramethylpiperidine (19.7ml, 117mmol) was added to a solution of n-butyl lithium (69.3ml of a 1.6M solution in hexane, lllmmol) in anhydrous THF (200ml) at -760C under an atmosphere of nitrogen, keeping the reaction temperature below -7O0C. The reaction mixture was stirred at -7O0C for 15 minutes then allowed to warm to O0C and stirred for a further 30 minutes before being cooled to -760C. 2-Chloropyrazine (1Og, 87.3mmol) was added dropwise such that the reaction temperature was kept below -7O0C. The reaction mixture was then stirred at -700C for 30 minutes. Ethyl formate (7.5ml, 98mmol) was then added such that the reaction temperature was kept below -700C. The reaction mixture was then stirred at -7O0C for 1.5 hours. Glacial acetic acid (13ml,.218mmol) was added at -7O0C and the mixture then allowed to warm to ambient temperature and the volatiles were removed by evaporation. The residue dissolved in ethanol (100ml) and hydroxylamine (6.83g, 105mmol) and triethylamine (24.2ml, 175mmol) were added. The mixture was heated at 500C for 18 hours and the volatiles were then removed by evaporation. The residue was dissolved in diethylether and any remaining insoluble material was removed by filtration. The filtrate was washed with water, the solvent removed from the organic layer by evaporation and the residue purified by chromatography on silica gel eluting with DCM, then with diethylether / DCM (1:4) and finally with EtOAc to give 3-chloropyrazine-2- carboxaldehyde oxime (5.21g, 37.9%) as a solid; NMR Spectrum 8.37 (s, IH), 8.50 (d, IH), 8.70 (d, IH), 12.25 (s, IH).
The synthetic route of 121246-96-6 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2006/106307; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem