Synlett 2020; 31(13): 1298-1302
DOI: 10.1055/s-0039-1690880
letter
© Georg Thieme Verlag Stuttgart · New York

A Convenient One-pot Synthesis of Chromenyl Acrylates and Acrylonitriles

Diogo Lopes
a   Department of Chemistry, University of Minho, Campus de Gualtar, Braga, Portugal   Email: fproenca@quimica.uminho.pt.com
,
Marta Costa
b   Life and Health Sciences Research Institute (ICVS), University of Minho, Campus de Gualtar, Braga, Portugal
c   ICVS/3B’s – PT Government Associate Laboratory, Braga/Guimarães, Portugal
,
João Louçano
a   Department of Chemistry, University of Minho, Campus de Gualtar, Braga, Portugal   Email: fproenca@quimica.uminho.pt.com
,
Fernanda Proença
a   Department of Chemistry, University of Minho, Campus de Gualtar, Braga, Portugal   Email: fproenca@quimica.uminho.pt.com
› Author Affiliations
Financial support was obtained from University of Minho, Fundação para a Ciência e a Tecnologia (FCT) and FEDERCOMPETE for financial support through Centro de Química (UID/QUI/00686/2013 and UID/QUI/0686/2016). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network (RNRMN) and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT. This work was also developed under the project NORTE-01-0145-FEDER-000013, by the Northern Portugal Regional Operational Program (NORTE 2020), through the European Regional Development Fund (FEDER) and the Competitiveness Factors Operational Program (COMPETE) and by national funds, through the Foundation for Science and Technology
(ref. POCI-01-0145-FEDER-007038).
Further Information

Publication History

Received: 26 February 2020

Accepted after revision: 16 March 2020

Publication Date:
02 April 2020 (online)


Abstract

2H-Oxo-chromenyl acrylates and 2H-imino-chromenyl acrylonitriles have been prepared from a salicylaldehyde and ethyl cyanoacetate or 2-amino-1,1,3-tricyanopropene, respectively. The reaction occurs in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) and the products were isolated in good to quantitative yields. Despite the simplicity of the synthesis, this is the first time that these substituted chromenes have been isolated.

Supporting Information

 
  • References and Notes

  • 4 Sugino A, Higgins NP, Brown PO, Peebles CL, Cozzarelli NR. Proc. Natl. Acad. Sci. USA 1978; 75: 4838
  • 7 Jones G. Org. React. 1967; 15: 204
  • 8 Vekariya RH, Patel HD. Synth. Commun. 2014; 44: 2756
  • 11 Fujimoto A, Sakurai A. Synthesis 1977; 871
    • 12a Phadtare SB, Shankarling GS. Environ. Chem. Lett. 2012; 363
    • 12b Ramani A, Chanda BM, Velu S, Sivasanker S. Green Chem. 1999; 1: 163
  • 14 Volmajer J, Toplak R, Leban I, Marechal AM. Tetrahedron 2005; 61: 7012
  • 15 Costa M, Areias F, Abrunhosa L, Venancio A, Proenca F. J. Org. Chem. 2008; 73: 1954
  • 16 Fujimoto A, Sakurai A. Synthesis 1977; 871
  • 17 Yang F, Wang Z, Wang H, Wang C, Wang L. RSC Adv. 2015; 5: 57122
  • 18 Ethyl 3-amino-2-cyano-3-(8-methoxy-2-oxo-2H-chromen-3-yl)acrylate (8b); Typical Procedure: DABCO (0.75 g, 6.68 mmol) was added to a solution of o-vanillin 6b (0.50 g, 3.29 mmol) and ethyl cyanoacetate 7a (880 μL, 8.26 mmol) in EtOH (30 mL). The mixture was heated at 80 °C in a closed vial and, after 15 min, a white solid started to precipitate. The white solid was filtered after 5 h 45 min and identified as 8b (0.96 g, 3.04 mmol, 92%). Mp 247–249 °C. 1H NMR (DMSO-d 6, 400 MHz): δ = 9.88 (s, 1 H, NH2), 9.18 (s, 1 H, NH2), 8.38 (s, 1 H, H4), 7.43 (dd, J = 2.4, 7.2 Hz, 1 H, H7), 7.34–7.40 (m, 2 H, H5 and H6), 4.18 (q, J = 7.2 Hz, 2 H, H5′), 3.94 (s, 3 H, OCH3), 1.23 (t, J = 7.2 Hz, 3 H, H6′). 13C NMR (DMSO-d 6, 100.6 MHz): δ = 166.4 (C3′), 164.2 (C1′), 156.9 (C2), 146.5 (C8), 144.6 (C4), 142.8 (C8a), 125.2 (C6), 122.7 (C3), 120.3 (C5), 118.3 (C4a), 118.1 (CN), 115.8 (C7), 71.4 (C2′), 59.9 (C5′), 56.3 (OCH3), 14.3 (C6′). Anal. Calcd for C16H19N2O5 (319): C, 60.40; H, 4.53; N, 8.81. Found: C, 60.29; H, 4.45; N, 8.89.
  • 19 Junek H, Wibmer P, Thierrichter B. Synthesis 1977; 560
  • 20 2-(Amino(2-imino-8-methoxy-2H-chromen-3-yl)methylene) malononitrile (11b); Typical Procedure: A solution of o-vanillin 6b (0.17 g, 1.14 mmol) and DABCO (0.12 g, 1.03 mmol) in EtOH (0.5 mL) was stirred in an ice bath. After about 1 min a suspension of 2-amino-1,1,3-tricyanopropene 12 (0.15 g, 1.14 mmol) in acetone (1.4 mL) was added. When the color of the suspension changed, the reaction mixture was connected to a vacuum system to remove the acetone. Stirring was concluded after 40 min, when a thick suspension was formed. The solid was filtered and washed sequentially with EtOH and cold acetone. Product 11b was isolated as a yellow solid (0.22 g, 0.83 mmol, 73%). Alternative Procedure: A solution of o-vanillin 6b (0.53 g, 3.48 mmol), N-methylpiperazine (772 μL, 6.96 mmol), EtOH (2 mL), 2-amino-1,1,3-tricianopropene 12 (0.46 g, 3.48 mmol), and acetone (2.5 mL) was stirred for 37 min. Product 11b was isolated as a yellow solid (0.76 g, 2.86 mmol, 82%). Mp > 300 °C (slow decomp. after 217 °C). 1H NMR (DMSO-d 6, 400 MHz): δ = 8.93 (s, 1 H, NH2), 8.91 (s, 1 H, NH2), 8.70 (s, 1 H, NH), 7.70 (s, 1 H, H4), 7.23 (dd, J = 1.6, 8.0 Hz, 1 H, H7), 7.16 (t, J = 7.6 Hz, 1 H, H6), 7.11 (dd, J = 1.6, 7.6 Hz, 1 H, H5), 3.86 (s, 3 H, OCH3). 13C NMR (DMSO-d 6, 100.6 MHz): δ = 168.3 (C2′), 151.9 (C2), 146.0 (C8), 142.6 (C8a), 137.0 (C4), 124.9 (C3), 123.9 (C6), 120.2 (C5), 118.4 (C4a), 116.6 (CN), 115.2 (C7), 115.1 (CN), 56.0 (OCH3), 49.6 (C1′). Anal. Calcd for C14H10N4O2 (266): C, 63.15; H, 3.79; N, 21.04. Found: C, 63.42; H, 3.98; N, 20.89.