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Melamine‐Functionalized Chitosan: A New Bio‐Based Reusable Bifunctional Organocatalyst for the Synthesis of Cyanocinnamonitrile Intermediates and Densely Functionalized Nicotinonitrile Derivatives
Author(s) -
Alirezvani Zahra,
Dekamin Mohammad G.,
Davoodi Farahnaz,
Valiey Ehsan
Publication year - 2018
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201802010
Subject(s) - malononitrile , thermogravimetric analysis , knoevenagel condensation , chemistry , bifunctional , melamine , catalysis , fourier transform infrared spectroscopy , thermal stability , organic chemistry , nuclear chemistry , polymer chemistry , chemical engineering , engineering
New covalently‐modified chitosan materials using 1,3‐dibromopropane and melamine (Cs−Pr−Me) were readily prepared at room temperature through a simple procedure and F characterized by the Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), thermal gravimetric analysis (TGA) and derivative thermogravimetric (DTG), energy‐dispersive X‐ray (EDX) spectroscopy, X‐ray powder diffraction (XRD) and CHN elemental analysis. The new Cs−Pr−Me bio‐derived materials were successfully investigated, as a heterogeneous bifunctional catalyst, for the Knoevenagel condensation of diverse aromatic aldehydes with malononitrile or ethyl cyanoacetate as well as for the synthesis of 2‐amino‐4,6‐biarylnicotinonitriles through four‐component condensation of 3‐acetylcoumarin, aromatic aldehydes, malononitrile and ammonium acetate. The catalyst could be simply reused several times with negligible loss of its activity. Avoiding the use of toxic transition metals or corrosive reagents for modification of the catalytic activity as well as high activity and stability of the catalyst are another distinguishing advantages of this new methodology.