Synthesis of 3-Aminoquinoline-2,4-(1H-3H)-Diones

摘要

Reaction of 3-chloro-(2) and 2-bromoquinoline-2,4-(1H,3H)-diones (3) with excess of primary alkyl-or arylamines in dimethylformamide provides the corresponding 3-alkyl-or 3-arylamino derivatives (4). Compounds (4) with the primary amino group at the 3 position were best prepared by reaction of 2 with in situ generated ammonia under anhydrous conditions. An alternative approach to the primary amines (4) via reduction of 3-azidoquinoline-2,4(1H,3H)-diones (5) was investigated. The reduction of 5 with zinc in acetic acid gave moderate to good yields of the desired products, while the reaction with triphenylphosphine afforded exclusively 4-hydroxyquinolin-2(1H)-one (1).