1: pyrazinecarbonitrile With trifluoroacetic acid in dichloromethane; water 0.25 h; 2: 3,4,5-trimethoxyphenylboronic acid With iron sulphate heptahydrate; dipotassium peroxodisulfate in dichloromethane; water T=20°C; 5 h; 3: With sodium hydroxide in dichloromethane; water T=20°C; Overall yield = 84 percent;

tetrakis(triphenylphosphine) palladium(0); caesium carbonate in N,N-dimethyl-formamide T=130°C; Inert atmosphereSealed tube;

triethylamine; zinc dibromide in acetonitrile 18 h; Heating;

1: POBr3 2: 4-methyl-pyridine View Scheme