Highly Selective Synthesis of α-Hydroxy, α-Oxy, and α-Oxo Amides by a Post-Passerini Condensation Transformation

Abstract

A post-Passerini condensation transformation can be employed in the synthesis of three types of amides: α-hydroxy, α-oxy, and α-oxo amides. K2CO3 efficiently promotes the solvolysis of α-acetoxy amides to form α-hydroxy amides in methanol. 2-Acetoxy-2-(2-alkynyl­quinolin-3-yl)acetamides in basic methanol are cyclized to 1,3-dihydrofuro[3,4-b]quinoline-1-carboxamides via deacetylation and 5-exo-dig cyclization. Treatment of 2-hydroxy-2-[2-(phenylethynyl)quinolin-3-yl]acetamides with I2 in basic media produces pyrrolo[2,3-b]quinoline-2,3-diones. This cyclization involves intramolecular cyclization, dealkynylative aromatization, and oxidation of the secondary alcohol.