UNEXPECTED CONVERSION OF 4-OXO-4<i>H</i>-CHROMENE-2-CARBOXYLIC ACID TO 2-(1,3-BENZOTHIAZOL-2-YL)-4<i>H</i>-CHROMEN-4-ONE AND SPIRO[1,4-BENZOTHIAZINE-2,2'-CHROMENE]-3,4'(3'<i>H</i>,4<i>H</i>)-DIONE

Authors

  • Fernando Cagide CIQUP/Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, Porto 4169-007, Portugal
  • Lígia R. Gomes Faculdade de Cíencias de Saúde, Escola Superior de Saúde, Universidade Fernando Pessoa, Praça de 9 de Abril, 349, Porto 4249-004, Portugal
  • John N. Low Department of Chemistry, University of Aberdeen, Meston Building, Meston Walk, Aberdeen, AB24 3UE, Scotland, United Kingdom
  • Fernanda Borges CIQUP/Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, Porto 4169-007, Portugal

DOI:

https://doi.org/10.1007/6322

Keywords:

2-aminobenzenethiol, 2-(1, 3-benzothiazol-2-yl)-4H-chromen-4-one, benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate, chromene-2-carboxylic acid, spiro[1, 4-benzothiazine-2, 2'-chromene]-3, 4'(3'H, 4H)-dione, phosphorus oxychloride, acidic vs basic conditions.

Abstract

2-(1,3-Benzothiazol-2-yl)-4H-chromen-4-one and spiro[1,4-benzothiazine-2,2'-chromene]-3,4'(3'H,4H)-dione have been synthesized from 4-oxo-4H-chromene-2-carboxylic acid. The course of the reaction that usually occurs between the activated carboxylic acid and aromatic amines was changed upon the use of different reaction conditions (acidic or basic) and 2-aminobenzenethiol. As a result, new heterocyclic derivatives were obtained. Structures of the compounds have been established on the basis of spectral (1D and 2D NMR spectra) and X-ray data.

Author Biographies

Fernando Cagide, CIQUP/Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, Porto 4169-007, Portugal

CIQUP/Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Porto, Portugal.

John N. Low, Department of Chemistry, University of Aberdeen, Meston Building, Meston Walk, Aberdeen, AB24 3UE, Scotland, United Kingdom

Department of Chemistry

Fernanda Borges, CIQUP/Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, Porto 4169-007, Portugal

CIQUP/Department of Chemistry and Biochemistry, Faculty of Science

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Published

2022-01-27

Issue

Vol. 58 No. 1 (2022)

Section

Short Communications