Synthesis of Substituted Coumarins and 2??Quinolinones by Cycloisomerisation of (Hydroxy/aminophenyl) propargyl Alcohols

M Sridhar Reddy, N Thirupathi…

Index: Sridhar Reddy, Maddi; Thirupathi, Nuligonda; Babu, Madala Hari European Journal of Organic Chemistry, 2012 , # 29 p. 5803 - 5809

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Citation Number: 13

Abstract

Abstract A new cycloisomerization strategy for the synthesis of coumarins and quinolinones is described. The addition of ethoxyacetylide to 2-hydroxyacetophenones directly resulted in 4-substituted coumarins by 6-endo-dig cycloisomerisation of the intermediate 3-ethoxy-1-(2- hydroxyphenyl)-2-propyn-1-ols. Under similar conditions, 2-aminoacetophenone produced 2-ethoxyquinoline, a masked quinolinone, which was converted into the quinolinone by ...