The preparation of 4-alkylaminoquinolines is most conveniently accomplished by coupling the appropriate amine with a 4-haloquinoline. In this Laboratory three principal methods have been investigated for the preparation of 4-haloquinolines. The Meisenheimer2 procedure is not generally applicable and, for example, is entirely unsatisfactory as a method for the preparation of 4,7-dichloroquinoline and 4-chloro-8-quinolinesulfonic acid. The oxalacetic ester synthesis3 is perhaps more general in application than the Meisenheimer but the cyclization and decarboxylation steps require conditions which vary widely depending upon the substituents in the carbocyclic ring. The most general method thus far developed is the ethoxymethylenemalonic ester synthesis. Ring closure of the anilinomethylenemalonic ester was first employed by Gould and Jacobs4 to prepare 3-carboxy-4-quinolinol. The decarboxylation of this acid gives more uniform results than obtained, with the 2-carboxy-4quinolinol from the oxalacetic ester synthesis. This method of synthesis has been widely used among the antimalarial contractors and was de-

No abstract

No abstract

No abstract

The Preparation of Some 4-Aminoquinolinf.s 1229 tion of 5-alkylamino-2-pentanone oximes. These and other diamines have been condensed with 4,7dichloroquinoline to give derivatives of 7-chloro-quinoline with aminoalkylamino or monoalkylaminoalkylamino substituents in the 4-position.Cambridge, Mass.