535921-11-0Relevant articles and documents
Efficient synthesis of trisubstituted [1]benzopyrano[4,3-b]pyrrol-4(1H)-one derivatives from 4-hydroxycoumarin
Liao, Yuan-Xiu,Kuo, Pei-Yu,Yang, Ding-Yah
, p. 1599 - 1602 (2007/10/03)
Various trisubstituted [1]benzopyrano[4,3-b]pyrrol-4(1H)-one derivatives have been synthesized from 4-hydroxycoumarin with a 30-40% yield over six steps. The key step of the synthesis is a base-promoted intramolecular cyclization of enamines 5, followed by dehydration to generate the fused pyrrole ring.