33332-29-5, 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 33332-29-5 as follows.
Step 2: 2,5-Dichloropyrazine; 5-Chloro-2-pyrazinamine (product of E1, step 1) (2.41g, 18.6mmole) was dissolved in concentrated hydrochloric acid (24ml), cooled in an ice-acetone bath and treated with a solution of sodium nitrite (2.63g, 38.1 mmole) in water (1 8ml) dropwise over a period of 1 hour. The mixture was cooled in an ice-water bath and left to stir for 1 hour. The mixture was allowed to warm to room temperature over 1 hour, neutralised by addition of sodium hydroxide solution (2M) and extracted with dichloromethane ( x 4). The dichloromethane layers were combined, dried under magnesium sulfate and evaporated in vacuo. The resulting residue was purified by column chromatography (1: 9 ethyl acetate: pentane) to afford the title compound (0.33g). ?H NMR (CDCl3) 8.40 (2H, s).
According to the analysis of related databases, 2-Amino-5-chloropyrazine, the application of this compound in the production field has become more and more popular.
Reference:
Patent; GLAXO GROUP LIMITED; WO2005/97778; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem