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

Reaction equation

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

Participants

Procedure

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 was stirred and refluxed for two hours. The reaction mixture was poured on ice, extracted with ethyl acetate, the organic extracts were dried and concentrated to yield an oil. The crude residue was eluted on a silica gel column with ethyl acetate-hexane (1:2) yielding the product of this example as a yellow solid, m.p. 72°-75° C.