Base catalyzed dimerization of ω-formyl-2-hydroxyacetophenones

Authors : Magdy Ahmed Ibrahim, Salah Sayed Ibrahim

Pages : 159-166

Doi:10.18596/jotcsa.10789

View : 5 | Download : 8

Publication Date : 2016-06-16

Article Type : Research Paper

Abstract :Refluxing ω-formyl-2-hydroxyacetophenones 1 in ethanol containing triethylamine as a basic catalyst produced the dimerized product identified as 2-insert ignore into journalissuearticles values(2-hydroxyaryl);-4 H ,5 H -pyrano[2,3- b ]chromen-5-ones 2 . Meanwhile, heating ω-formyl-2-hydroxyacetophenones 1 in 2M aqueous sodium hydroxide solution afforded another type of dimeric product identified as 3-[2-insert ignore into journalissuearticles values(2-hydroxy-5-substituted benzoyl);vinyl]-6-substituted-4 H -chromen-4-ones 3 . The proposed mechanisms were discussed. The mode of dimerization of ω-formyl-2-hydroxyacetophenones 1 depends on the type of catalyst used and the reaction conditions. Structures of the synthesized compounds were deduced on the basis of their analytical and spectral data.
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