Direct observation of 1-azafulven-6-one and annelated derivatives
Abstract
1-Azafulven-6-one, 2-carbonyl-2H-indole, 5-carbonyl-5H-furo[3,2-b]pyrrole, and thieno- and pyrrolo-analogues are isolated at low temperatures following thermal elimination of water or methanol from the corresponding carboxylic acids or esters; the azafulvenones dimerise at –100 to –40 °C to diketopiperazine derivatives.