European Journal of Chemistry 6 (4) (2015) 387‐393 European Journal of Chemistry Journal webpage: www.eurjchem.com An unexpected tandem cycloaddition reaction of α,β‐unsaturated acid chloride with amines: Synthesis of dihydropyrancarboxamide derivatives and biological activity Abdel‐Zaher Abdel‐Aziz Elassar Chemistry Department, Faculty of Science, Ain Helwan, Helwan University, Cairo, 11795, Egypt * Corresponding author at: Chemistry Department, Faculty of Science, Ain Helwan, Helwan University, Cairo, 11795, Egypt. Tel.: +2.01.014451887. Fax: +2.02.25552468. E‐mail address:
[email protected] (A.Z.A.A. Elassar). ARTICLE INFORMATION ABSTRACT Tandem cycloaddition reaction of α,β‐unsaturated acid chloride with amines afforded in situ N‐acylated amines, which undergoes cycloaddition reaction with other molecule of acid chloride to give dihydropyran carboxamide derivatives as an unexpected product. 2‐Amino benzimidazole, 2‐aminobenzthiazole, 2‐aminothiazole, anthranilic acid, o‐pheneylenediamine, and 3‐methyl‐1H‐pyrazol‐5(4H)‐one are reacted with methacryloyl chloride at 0 °C to give different derivatives of dihydropyran carboxamide. The latter compound was obtained through acylation of the organic amines followed by tandem cycloaddition reaction. In contrast acryloyl chloride afforded only N‐acylated derivatives. Both products are DOI: 10.5155/eurjchem.6.4.387‐393.1306 characterized by single crystal X‐ray diffraction method. Bioactivity of the newly synthesized products was studied against Gram‐positive, Gram‐negative bacteria and fungus. Received: 20 July 2015 Accepted: 22 August 2015 Published online: 31 December 2015 Printed: 31 December 2015 KEYWORDS Synthesis Biological activity Cycloaddition reaction Single crystal structure Tandem cycloaddition reaction Cite this: Eur. J. Chem. 2015, 6(4), 387‐393 Dihydropyrancarboxamide derivatives 1.