Cyclic imides IV. The reaction of some N‐substituted nitrophthalimides with sodium methoxide

Treatment of methyl 4‐nitrophthalimidoacetate (I) with sodium methoxide in refluxing methanol results in a Gabriel‐Colman rearrangement to give 7 ‐ nitro‐4‐hydroxy‐3‐carbomethoxy‐1(2H) ‐ isoquinolone (II). Under the same conditions, N‐substituted 3‐nitrophthalimides (IV) yield N‐substituted 3‐methoxyphthalimides (V).