5-乙基-2-吲哚酮的合成及其酰基化和N上烃基化反应研究

Synthesis,acylation and N-alkylation of 5-ethyllindolin-2-one

以4-乙基苯胺1为原料,经Sandmeyer反应得5-乙基靛红2;2经水合肼还原得到5-乙基-2-吲哚酮3;N,N-二甲基甲酰胺与三氯氧磷先形成Vilsmeier-Haack试剂,再与化合物3反应,合成2-氯-5-乙基-3-乙酰吲哚4;以丙酮为溶剂,对化合物4烃基化,以78.5%-95.6%的收率得到N-取代-2-氯-5-乙基-3-乙酰吲哚5a-5e。其中化合物4、5a-5e均未见文献报道,它们的结构均通过红外光谱、核磁共振氢谱(碳谱),质谱等确认。

4-Ethylaniline 1 was first underwent the Sandmeyer reaction to give 5-ethylisatin 2,which was then subjected to the reduction reaction with hydrazine hydrate to give the corresponding 5-ethyllindolin-2-one 3. The 3 was treated with Vilsmeier reagent,prepared from N,N-dimethylacetamide（ DMA） with POCl3 to afford the structurally new 3-acetyl-2-choloro-5-ethyl-indole 4. Subsequently,the obtained product 4 was further alkylated in acetone as solvent to give the corresponding 3-acetyl-N-alkyl-2-chloro-5-ethylindoles 5a-5e in good yields of 78. 5%-95. 6%. The structures of the newly-synthesized compounds 4 and 5a-5e were confirmed by IR,MS,1H and13 C NMR analyses.