Phthalimides. I. Base-catalyzed Lossen Rearrangement and Acid-catalyzed Beckmann Rearrangement with<i>N</i>-(Arylsulfonyloxy)phthalimides
作者:A. F. M. Fahmy、N. F. Aly、A. Nada、N. Y. Aly
DOI:10.1246/bcsj.50.2678
日期:1977.10
N-(Arylsulfonyloxy)phthalimides undergo base-catalyzed Lossen rearrangement with amines, and amino acids to give N,N′-diaryl ureas and amine salts. They behave similarly with phenylhydrazine in alcohol to give a mixture of N-hydroxyphthalimide and phenylhydrazine salts. However, N-(arylsulfonyloxy)phthalimides undergo isomerization followed by Beckmann rearrangement to give a mixture of 4-aryl-1H-2,3-benzoxazin-1-ones
A direct approach for the synthesis of N3-substituted quinazoline-2,4-diones via condensation of isatoic anhydrides with amines mediated by Ph3P-I2 was reported. Instead of the expected benzoxazinones, the reaction proceeds with an amine attack at the C-4 position of isatoic anhydrides leading to quinazoline-2,4-diones upon heating in the presence of base. This one-pot process enables a rapid construction