title: Synthetic approaches to multifunctional indenes.
abstract: The synthesis of multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such as the [3-(aminoethyl)inden-5-yl)]amines, a reasonable pathway involves the (5-nitro-3-indenyl)acetamides as key intermediates. Although several multistep synthetic approaches can be applied to obtain these advanced intermediates, we describe herein their preparation by an aldol-type reaction between 5-nitroindan-1-ones and the lithium salt of N,N-disubstituted acetamides, followed immediately by dehydration with acid. This classical condensation process, which is neither simple nor trivial despite its apparent directness, permits an efficient entry to a variety of indene-based molecular modules, which could be adapted to a range of functionalized indanones.
authors.affiliation: Laboratori de Química Orgànica, Departament de Farmacologia i Química Terapèutica, Facultat de Farmàcia, Universitat de Barcelona, Avda. Joan XXIII s/n, 08028 Barcelona, Spain.
authors.forename: Neus
authors.initials: N
authors.lastname: Mesquida
authors.forename: Sara
authors.initials: S
authors.lastname: López-Pérez
authors.forename: Immaculada
authors.initials: I
authors.lastname: Dinarès
authors.forename: Ermitas
authors.initials: E
authors.lastname: Alcalde