| 摘要 |
PURPOSE: Provided is a preparation method of secondary amide in high purity and yield from tertiary amide by elimination of β-substituted α-arylalkyl group in reaction with protonic acid in organic solvent. The α-arylethylamine or α-aryl-β-substituted ethylamine is used as a nitrogen source in synthesis of biologically active compounds. CONSTITUTION: The synthesis of the secondary amide is characterized by making a tertiary amide represented by the formula(2) react with protonic acid in organic solvent to manufacture a secondary amine represented by the formula(1) by stirring at 10-150 deg.C for 2-24 hours. In the formulae, R1 is C1-5 alkyl, C3-7cycloalkyl, heterocyclic or C6-15 aryl group substituted with one or more groups selected from low alkyl with C1-4, hydroxy, animo, halogen, alkoxy, monoalkylamino, dialkylamino and carboxyl group; R2 is C1-5 alkyl group substituted with more than one group selected from amino, hydroxy, mono alkylamino, alkoxy and halogen; Ar is phenyl or α- or β-naphthyl group substituted by one or more groups selected from halogen, methoxy, carbamoyl, sulfamoyl, nitro group; R3 is C6-15 alkyl, phenyl or heterocyclic group substituted by one or more groups selected from C1-4 low alkyl, hydroxy, amino, halogen, alkoxy, mon alkylamino, dialkyl amino, carboxyl, carbamoyl, sulfamoyl, nitro or cyano group; and R1 and R3 are connected to form a 5 or 6 membered ring. The protonic acid is selected from hydrochloric acid, acetic acid, trifluoroacetic acid and methanesulfonic acid.
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