101865-05-8Relevant articles and documents
Synthesis of 2,6-dioxo-1,2,3,4,5,6-hexahydroindoles by acid-catalyzed cyclization of acetal-protected (2,4-dioxocyclohex-l-yl)acetamides and their transformation into 5,8,9,10-tetrahydro-6H-indolo[2,1-a]isoquinolin-9-ones
Juma, Benard,Adeel, Muhammad,Villinger, Alexander,Reinke, Helmut,Spannenberg, Anke,Fischer, Christine,Langer, Peter
supporting information; experimental part, p. 1073 - 1079 (2009/12/05)
Acetal-protected (2,4-dioxocyclohex-1-yl)-acetic acids were prepared by allylation of dilithiated 1,3-cyclohexane-1,3-diones, protection of the carbon-yl groups and oxidation of the alkene moiety. Their reaction with amines afforded the corresponding amides which were transformed, by acid-catalyzed cyclization, into various 2,6-dioxo-1,2,3,4,5,6-hexahy-droindoles. The reaction of the latter with triflic acid resulted in the formation of novel 5,8,9,10-tetrahy-dro-6H-indolo[2,1-a]isoquinolin-9-ones.