Synthesis And Characterization Of Novel Heterocyclic Compounds Containing5-alkyl(Oxy)isatin Skeleton

Isatin, namely indole-2,3-dione, is present as a basic skeleton core in many organisms. Due to theirimportant role and great potential in pesticides, pharmaceuticals, dyes, and the life sciences, isatin and itsderivatives have drawn much attention of chemists. In this thesis, we selected5-alkyl-and5-alkoxylisatin as starting materials to construct different types of poly-functional isatin derivatives, which could beused as useful building block for organic synthesis. This thesis is consist of four parts.The first part gives a simple review concerning the property, synthesis and application of isatin on thebasis of a survey of related literature.In the second part,5-alkyl(oxy)isatins (1a-1c) were first synthesized using p-alkyl(oxy)anilines asraw materials. N-alkylation reaction of1a-1c gave the corresponding N-substituted-5-alkyl oralkoxylisatin (2a-2o), which were then reacted with hydrazine hydrate under reflux conditions to affordN-substituted-5-alkyl or alkoxyl indolones (3a-3o). By the treatment with acetic anhydride, compounds3a-3o were converted into N-substituted-2-hydroxy-3-acetyl-5-alkyl or alkoxy indoles (4a-4o).The third part described the synthesis of5H-[1,2,4] triazines (5a-5c) and [5.6-b] indol-3-thiolderivatives (6a,7a-7n) with the yields of70.9%-85.0%through the ring-closure reaction of5-alkyl oralkoxylisatin (1a-1c) or N-substituted-5-alkyl or alkoxylisatin (2a-2o) with thiosemicarbazone underreflux condition.The last part involved the synthesis of novel quindoline alkaloids,2-substituted6,9-dimethyl-6H-indole [2,3-b] quinolin-11-carboxylic acid (12a-12g).5-Methylisatin (1a) as the startingmaterial reacted with hydrazine hydrate to give indolone (8a), which was converted into2-chloro-3-acetyl-5-methyl indole (9a) via Vilsmeier reaction. And then N-methylation and2-substitutionreaction of9a afforded N-methyl-2-ethoxy-3-acetyl-5-methylindole (11a), which was further reacted withisatin and substituted isatins to give the desired quindoline alkaloids (12a-12g) in yields of32.7-43.2%.All the synthesized compounds were characterized with IR、1H NMR、13C NMR and MS.