Synthetic Route of 22047-25-2, In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 22047-25-2 as follows.
1) 1-(6-Chloro-3-pyridazinyl)-5-(2-pyrazinyl)-1H-pyrazole-3-carboxylic acid methyl ester Under cooling to -78C, lithium bis(trimethylsilyl) amide(a 1.0 M solution in tetrahydrofuran, 55.0 mL) was added to a solution of 1-(2-pyrazinyl)-1-ethanone (6.10 g) in tetrahydrofuran (50 mL), and the resultant mixture was stirred for 45 minutes. Dimethyl oxalate (8.85 g) was added to the reaction solution, and the mixture was stirred for 10 minutes. Then, while slowly returning the temperature of the mixture to room temperature, the mixture was stirred for 2.5 hours. Diethyl ether and water were added to the reaction solution, and the mixture was partitioned. An aqueous 1 N hydrochloric acid solution (55 mL) was added to the aqueous layer, and the aqueous layer was further saturated with sodium chloride, and then extracted with diethyl ether. The organic layers were combined and dried over anhydrous sodium sulfate. After separation by filtration, the solvent was evaporated under reduced pressure, and 4-(2-pyrazinyl)-2, 4-dioxobutanoic acid methyl ester (10.0 g, 96%) was obtained as a solid. To a suspension of a crude product of this butanoic acid methyl ester product (6.27 g) in methanol (150 mL), 3-chloro-6-hydrazinopyridazine (4.35 g) was added, and the mixture heated to reflux for 18.5 hours. Concentrated hydrochloric acid (0. 750 mL) was further added to the reaction solution, and the mixture was heated to reflux for 2 hours. After air cooling, ethyl acetate and a saturated aqueous solution of sodium hydrogen carbonate were added to the reaction solution, and the mixture was partitioned. The organic layer was dried over anhydrous sodium sulfate. After separation by filtration, the solvent was evaporated under reduced pressure, and methanol was added to the residue thus obtained. The precipitated solid was filtered, and 1-(6-chloro-3-pyridazinyl)-5-(2-pyrazinyl)-1H-pyrazole-3-carboxylic acid methyl ester (5.74 g, 60%) was obtained as a solid. 1H-NMR(400MHz, CDCl3)delta: 4. 02 (3H, s), 7.33(1H, s), 7.72(1H, d, J=9.3Hz), 8.16(1H, d, J=9.0Hz), 8.42(1H, dd, J=2.4, 1.5Hz), 8.57(1H, d, J=2.7Hz), 8.90(1H, d, J=1.5Hz). ESI-MSm/z: 317[(M+H)+, 35Cl], 319[(M+H)+, 37Cl].
According to the analysis of related databases, 22047-25-2, the application of this compound in the production field has become more and more popular.
Reference:
Patent; DAIICHI PHARMACEUTICAL CO., LTD.; EP1785418; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem