2(1H)-Pyrazinone, which is in equilibrium with 2-pyrazinol, reacts with benzonitrile oxide (BNO) affording the N-1-adduct with a 67% yield, while 2-methoxypyrazine gives two methoxypyrazinones (ca. 3%) and a biscycloadduct together with its degradation product, which derive from the two unisolable monocycloadducts to the C=N-4 double bond. N-Methylpyrazinone gives only the degradation product (3.4%) of the initial monocycloadduct of BNO to C=N-4 doable bond.
2(1H)-Pyrazinone, which is in equilibrium with 2-pyrazinol, reacts with benzonitrile oxide (BNO) affording the N-1-adduct with a 67% yield, while 2-methoxypyrazine gives two methoxypyrazinones (ca. 3%) and a biscycloadduct together with its degradation product, which derive from the two unisolable monocycloadducts to the C=N-4 double bond. N-Methylpyrazinone gives only the degradation product (3.4%) of the initial monocycloadduct of BNO to C=N-4 doable bond.