Synthesis
The general procedure for the synthesis of 4-(pyrazin-2-yl)benzaldehyde from 2-chloropyrazine and 4-hydroxymethylphenylboronic acid was as follows: to a 10 mL round bottom flask were added the specified amount of Pd/Cu catalyst, 2-chloropyrazine (0.5 mmol), 4-hydroxymethylphenylboronic acid (0.75 mmol), Cs2CO3 (1.0 mmol), and 5 mL dioxane. The reaction mixture was placed in an oil bath and heated at 110 °C for 24 hours. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure. The resulting residue was purified by rapid chromatography on silica gel using dichloromethane (CH2Cl2) as eluent. The products 4a-k and 4m are known compounds except 4l and 4n [6,9].
References
[1] Inorganica Chimica Acta, 2014, vol. 423, # PART A, p. 11 - 15
[2] Inorganica Chimica Acta, 2014, vol. 423, # 1, p. 11 - 15
[3] Inorganica Chimica Acta, 2014, # PA, p. 11 - 15
