Studies On Synthesis Of Heterocycles Such As Spiro And Quinolinones By Cyclization Of Alkynes

Due to spiro trienone and quinolinone derivatives, especially nitrogencontaining heterocycles have special physiological activity, therefore, they were applied widely in many territory, such as organic intermediates of medicine and pesticide, functional materials and antibacterial agent etc. In consideration the importance and the practicability of spiro trienone and quinolinone derivatives, a new effective synthesis method for these compounds was developed depend on the existing synthesis methods.(1) This paper synthesized a series of alkynes compounds by aniline and propiolic acid as raw material. We developed a new kind of efficient synthesis of Spiro [4, 5] trienone derivatives with alkynes compounds synthesis method. This reaction was was N-methyl-N, 3-diphenyl- propiolamide as the substrate. The optimal conditions of this experiment were obtained via screening of oxidant, catalyst, solvent, reaction time and reaction temperature. The best reaction conditions were 0.2 mmol N-methyl-N,3- diphenyl- propiolamide as substrate, 2 equiv TBHP as a catalystoxidant, 1.2 equiv Fe Br3 as catalyst radicals provider reagent, 2 m L Et OAc as solvent, filled with N2, reaction temperature was 100℃, synthesis time was 20 h. 86% of target product was obtained. The reaction conditions were simple, environmentally friendly and higher yields.(2) The experiment displayed that a series of quinoline ketone derivatives were successfully prepared through cyclization of alkynes, including transition metal-catalyzed in-tramolecular cyclization reactions with catalyst iron. This reaction was was N-methyl-N, 3-diphenyl- propiolamide as the substrate. The optimal conditions of this experiment were obtained via screening of oxidant, catalyst, solvent, reaction time and reaction temperature. The best reaction conditions were 4 equiv K2S2O8 as oxidant, 1.5 equiv Fe Br3 as catalyst radicals provider reagent, 2 m L Me CN as solvent, filled with O2, reaction temperature was 100℃, synthesis time was 20 h. 91% of target product was obtained. The reaction condition were simple, higher yields and environment friendly.