Synthesis 2018; 50(02): 267-277
DOI: 10.1055/s-0036-1591835
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© Georg Thieme Verlag Stuttgart · New York

Palladium-Catalyzed Carbonylative Synthesis of Functionalized Benzimidazopyrimidinones

Raffaella Mancuso
a   Laboratory of Industrial and Synthetic Organic Chemistry (LISOC), Department of Chemistry and Chemical Technologies, University of Calabria, Via Pietro Bucci 12/C, 87036 Arcavacata di Rende (CS), Italy   Email: lucia.veltri@unical.it   Email: bartolo.gabriele@unical.it
,
Lucia Veltri*
a   Laboratory of Industrial and Synthetic Organic Chemistry (LISOC), Department of Chemistry and Chemical Technologies, University of Calabria, Via Pietro Bucci 12/C, 87036 Arcavacata di Rende (CS), Italy   Email: lucia.veltri@unical.it   Email: bartolo.gabriele@unical.it
,
Patrizio Russo
a   Laboratory of Industrial and Synthetic Organic Chemistry (LISOC), Department of Chemistry and Chemical Technologies, University of Calabria, Via Pietro Bucci 12/C, 87036 Arcavacata di Rende (CS), Italy   Email: lucia.veltri@unical.it   Email: bartolo.gabriele@unical.it
,
Giuseppe Grasso
a   Laboratory of Industrial and Synthetic Organic Chemistry (LISOC), Department of Chemistry and Chemical Technologies, University of Calabria, Via Pietro Bucci 12/C, 87036 Arcavacata di Rende (CS), Italy   Email: lucia.veltri@unical.it   Email: bartolo.gabriele@unical.it
,
Corrado Cuocci
b   Istituto di Cristallografia, CNR, Via Amendola 122/O, 70124 Bari, Italy
,
Roberto Romeo
c   Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Via SS Annunziata, 98168 Messina, Italy
,
a   Laboratory of Industrial and Synthetic Organic Chemistry (LISOC), Department of Chemistry and Chemical Technologies, University of Calabria, Via Pietro Bucci 12/C, 87036 Arcavacata di Rende (CS), Italy   Email: lucia.veltri@unical.it   Email: bartolo.gabriele@unical.it
› Author Affiliations
Further Information

Publication History

Received: 28 September 2017

Accepted after revision: 25 October 2017

Publication Date:
23 November 2017 (online)


Abstract

A new and convenient approach to functionalized benzimidazopyrimidinones is reported. It is based on a two-step procedure starting from readily available 1-(prop-2-yn-1-yl)-1H-benzo[d]imidazol-2-amines, consisting of a multicomponent palladium-catalyzed oxidative cyclocarbonylation–alkoxycarbonylation process, followed by base-promoted isomerization of the initially formed mixture of isomeric carbonylated products. Fair to good overall yields of the final alkyl 2-(2-oxo-1,2-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidin-3-yl)acetates are obtained, using different alcohols as solvent and nucleophile in the carbonylation step (carried out in the presence of 0.33–1 mol% PdI2 in conjunction with 17–50 mol% KI, at 100 °C and under 20 atm of a 4:1 mixture of CO–air) and the corresponding sodium alkoxide as base in the subsequent isomerization step (carried out in the alcoholic solvent at room temperature). The structures of a representative substrate [N-benzyl-1-(prop-2-yn-1-yl)-1H-benzo[d]imidazol-2-amine] and a representative product [methyl 2-(1-isopentyl-2-oxo-1,2-dihydrobenzo-[4,5]imidazo[1,2-a]pyrimidin-3-yl)acetate] were confirmed by X-ray diffraction analysis.

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