反应详情

温度

35 °C

A mixture of 2,3-dimethylpyrazine (25 g, 0.23 mol) and 30% H2O2 (52.4 g, 0.46 mol) in acetic acid (74 mL) was stirred for two days at 35° C. The solvent was removed under vacuum. Water was added and the mixture evaporated again. The residue was basified with aqueous K2CO3 and extracted with EtOAc. The organic phases were dried over Na2SO4 and concentrated. The resulting solid combined from two batches was recrystallized from cyclohexane to give 2,3-dimethylpyrazine 1-oxide (27 g, 47%). 1HNMR (CDCl3, 300 MHz) δ 8.18 (d, J=3.9 Hz, 1H), 8.02 (d, J=4.2 Hz, 1H), 2.58 (s, 3H), 2.48 (s, 3H).

1. customThe solvent was removed under vacuum
2. additionWater was added
3. customthe mixture evaporated again
4. extractionextracted with EtOAc
5. dry with materialThe organic phases were dried over Na2SO4
6. concentrationconcentrated
7. customwas recrystallized from cyclohexane