| 摘要 |
<p>Nitrogen-substituted imides of the formula: wherein R represent (i) an alkyl radical containing from 1 to 8 carbon atoms, or (ii) an aryl radical containing 1 or 2 phenyl nuclei optionally carrying 1 to 5 substituents selected from the group consisting of halogen atoms (1, 2 or 3), nitro, amino and hydroxy groups (1 or 2), alkyl radicals (1 to 4), alkoxy radicals(1 or 2) containing from 1 to 4 carbon atoms and alkylthio radicals(1 or 2) containing from 1 to 4 carbon atoms, or (iii) a hexyl radical optionally substituted by 1, 2 or 3 halogen atoms, and R1 represents a single bond or an optionally substituted, saturated or unsaturated hydrocarbon chain containing from 1 to 4 carbon atoms, it being possible for two adjacent carbons to form part of a phenyl radical, are prepared by this cyclisation of an amic acid of the formula:(wherein R and R1 are hereinbefore defined, and R2 represents a hydrogen atom, an alkali metal atom, an ammonium group, or an alkyl radical containing from 1 to 4 carbon atoms) in the presence of a mixed catalyst resulting from the association of the formula A B, wherein A represents a strong inorganic or organic acid, and B represents a Lewis base.</p> |
