p-Toluenesulfonic acid → Methyl 3-anilinopyrazine-2-carboxylate

Reaktionsgleichung

Br[C:2]1[C:7]([C:8]([O:10][CH3:11])=[O:9])=[N:6][CH:5]=[CH:4][N:3]=1.[NH2:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>O>[C:13]1([NH:12][C:2]2[C:7]([C:8]([O:10][CH3:11])=[O:9])=[N:6][CH:5]=[CH:4][N:3]=2)[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Komponenten

Versuchsvorschrift

A mixture of 9.5 g. of methyl 2-bromo-3-pyrazine carboxylate, 8.2 g. of aniline, 0.5 g. of p-toluene sulfonic acid and 100 ml. of water is stirred and refluxed for two hours. The reaction mixture is poured on ice, extracted with ethyl acetate, the organic extracts are dried and concentrated to yield an oil. The crude residue is eluted on a silica gel column with ethylacetate-hexane (1:2) yielding the product of this example as a yellow solid, m.p. 72°-75° C.