Synthesis 2019; 51(15): 2965-2976
DOI: 10.1055/s-0037-1612428
paper
© Georg Thieme Verlag Stuttgart · New York

Synthesis and Photophysical Properties of 1,4-Dihydro-2H,5H-chromeno[4,3-d][1,3]oxazin-5-ones, and Derivatives Containing Tethered 1,2,3-Triazoles, from 4-Aminocoumarins

Marina C. Dilelio
a   Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil   Email: silveira@quimica.ufsm.br
,
Nathan P. Brites
a   Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil   Email: silveira@quimica.ufsm.br
,
Larissa A. Vieira
a   Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil   Email: silveira@quimica.ufsm.br
,
Bernardo A. Iglesias
a   Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil   Email: silveira@quimica.ufsm.br
,
b   Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
,
a   Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil   Email: silveira@quimica.ufsm.br
› Author Affiliations
The authors are thankful to Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Grant 429158/2018-1), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET, PUE IQUIR 2016).
Further Information

Publication History

Received: 28 January 2019

Accepted after revision: 15 March 2019

Publication Date:
10 April 2019 (online)


Abstract

A facile protocol for the unprecedented one-pot H2SO4-mediated hydroxymethylation/cyclative N,O-acetalization of 4-aminocoumarins to 1,4-dihydro-2H,5H-chromeno[4,3-d][1,3]oxazin-5-ones, in moderate to good yields, was developed and optimized. The scope and limitations of the transformation, which takes place in water or water/THF mixtures, were also studied. The nitrogen atom of the resulting tricycles was used to tether alkyl, aryl and 1,2,3-triazolylmethyl moieties, employing a two-step click chemistry approach for the latter. The photophysical properties of the heterocycles, as well as of their 1,2,3-triazole derivatives, were also examined. The N-aryl derivatives exhibited high quantum yields of fluorescence (up to Φf = 0.69) and very large Stokes shifts (up to 201 nm).

Supporting Information