N-Benzyl-6-chloro-2-pyrazinamine synthesis

4774-14-5

100-46-9

426829-61-0

Step 1: Synthesis of N-benzyl-6-chloro-2-pyrazinamine. A mixture of 2,6-dichloropyrazine (1.31 g, 8.8 mmol), benzylamine (1.15 g, 10.7 mmol) and potassium carbonate (K2CO3, 1.65 g, 11.9 mmol) in acetonitrile (6 mL) was heated in a sealed heat-resistant glass flask and reacted for 13 hr at 85 °C. Upon completion of the reaction, the reaction mixture was diluted with dichloromethane and filtered to remove insoluble salts, followed by concentration of the filtrate under reduced pressure. The yellow solid residue obtained was dissolved in a small amount of methanol and initially purified by silica gel column chromatography (18 × 4 cm) using chloroform/methanol (98:2, v/v) as eluent first. Subsequently, a second purification was carried out by silica gel column chromatography (16×4 cm) using chloroform as eluent to afford 1.55 g (81% yield) of 2-chloro-6-benzylaminopyrazine as a light yellow solid. The result of high resolution mass spectrometry (HRMS) analysis: m/z calculated value of C11H10ClN3(M)+ was 219.0563, and the measured value was 219.0568. The result of elemental analysis (C11H10ClN3) was in accordance with the theoretical value.